What is Supersymmetry: Definition and 132 Discussions

In particle physics, supersymmetry (SUSY) is a conjectured relationship between two basic classes of elementary particles: bosons, which have an integer-valued spin, and fermions, which have a half-integer-valued spin. A type of spacetime symmetry, supersymmetry is a possible candidate for undiscovered particle physics, and seen by some physicists as an elegant solution to many current problems in particle physics if confirmed correct, which could resolve various areas where current theories are believed to be incomplete. A supersymmetrical extension to the Standard Model could resolve major hierarchy problems within gauge theory, by guaranteeing that quadratic divergences of all orders will cancel out in perturbation theory.
In supersymmetry, each particle from one group would have an associated particle in the other, known as its superpartner, the spin of which differs by a half-integer. These superpartners would be new and undiscovered particles; for example, there would be a particle called a "selectron" (superpartner electron), a bosonic partner of the electron. In the simplest supersymmetry theories, with perfectly "unbroken" supersymmetry, each pair of superpartners would share the same mass and internal quantum numbers besides spin. Since it is expected to find these "superpartners" using present-day equipment, if supersymmetry exists then it consists of a spontaneously broken symmetry, allowing superpartners to differ in mass. Spontaneously broken supersymmetry could solve many problems in particle physics, including the hierarchy problem.
There is no experimental evidence that supersymmetry is correct, or whether or not other extensions to current models might be more accurate. It is only since around 2010 that particle accelerators specifically designed to study physics beyond the Standard Model have become operational (i.e. the Large Hadron Collider (LHC)), and it is not known where exactly to look, nor the energies required for a successful search.
The main reasons for supersymmetry being supported by some physicists is that the current theories are known to be incomplete and their limitations are well established, and supersymmetry could be an attractive solution to some of the major concerns.

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  1. S

    Quantum Clifford Algebra for Quantum Field Theory, Supersymmetry, Supergravity

    I'm currently trying to learn Clifford algebra or more specifically spinors, in higher dimensions. My goal is to study AdS/CFT, but an essential part of learning it is to understand SUSY which then needs some element of Clifford algebra in higher dimensions. I have consulted, Introduction to...
  2. R

    A Why don't we see super-symmetric particles?

    we can se many particles, also we can detect and produce antimatter however my question is why even at high energies we can not see any supersymmetric partner of a particle ?
  3. arivero

    I Spontaneous Symmetry Breaking and quantum mechanics

    Confronted with my inability to grasp Witten's Susy QM examples of supersymmetry breaking, I concluded that the problem was that I was not understanding spontaneous symmetry breaking in simpler contexts. It seems that SSB is not possible in QM because of tunneling between the different states...
  4. arivero

    A Roles of supersymmetry in mathematics?

    Considering the definition of supersymmetry as a set of operators that extend the transformations of Poincare group, I wonder if they are of some value for mathematics, particularly for differential geometry. Most of the formalism I can find relate to "superspace", which does not seem a natural...
  5. kakaho345

    A Cohomology and fermions in supersymmetry

    Hello, I have been looking at some differential geometry and watching Hirosi's video lecture online: At 1:03:00, I found that they claimed that there is a correspondence between the Hibert space of the symmetric Hamiltonian and the cohomology of the manifold. I am super new to the subject and...
  6. TheHeraclitus

    I Is Supersymmetry required by String theory?

    From what I understood Supersymmetry means there are more particles than we currently know about and they are predicted by (some/all, I do not know) versions of String theory. Is it so important to String theory or can it work without SUSY? Thank you!
  7. Safinaz

    A How Randall-Sundrum model has solved the hierarchy problem?

    I'm trying to understand how the RS model solved the hierarchy problem from this mass relation $$ M^2_p = \frac{M^3}{k} \Large[1- e^{-2k\pi r} \Large],$$ Equ. 16 in their paper: https://arxiv.org/abs/hep-ph/9905221 With k as large as the Planck scale, the exponential will be so small and...
  8. Tianluo_Qi

    Quantum Reading list recommendation for HEP-ph to HEP-th/math-ph transition

    One sentence summarization For a student initially working on a more phenomenological side of the high energy physics study, what is the recommendation of introductory reading materials for them to dive into a more mathematically rigorous study of the quantum field theory. Elaboration...
  9. shrey07

    B Supersymetry versus Anti Particles?

    What is the difference between an anti particle and a super-partner? Would SIMPs fall under the supersymmetry theory, or the anti particle theory, or both?
  10. G

    I Are Supersymmetry Sparticles Paired with Antimatter Counterparts?

    In supersymmetry, are there corresponding antimatter particles to the Susy sparticles similar to the corresponding standard model antimatter particles, e.g., antiselectron, etc.?
  11. D

    A Supersymmetry: A Fundamental Principle or Just Bookkeeping?

    Just very recently I was looking into the subject of supersymmetry. Consider expressions of the form $$ \mathcal{L} = \frac{1}{4\pi} \int_{M^4} d^4x d^2\theta \tau_0(\Lambda_0) \mathrm{Tr} W_\alpha W^\alpha \ + \frac{1}{4\pi} \int_{M^4} d^4x d^2\theta \ \mathrm{Im} \...
  12. S

    A High energy symmetry breaking and laws of physics?

    In some models of the beginning of the universe, like for example in chaotic inflation, space would stop expanding in some points, creating Hubble volumes that could experience different spontaneous symmetry breaking, which would result in different properties, such as different physical...
  13. Q

    A Invariance of discrete Spectrum with respect a Darboux transformation

    According to this this the Darboux transformation preserves the discrete spectrum of the Haniltonian in quantum mechanics. Is there a proof for this? My best guess is that it has to do with the fact that $$Q^{\pm}$$ are ladder operators but I'm not sure.
  14. M

    A Seeking the Standard Model in E8 plus Supersymmetry

    This is just a quick alert regarding a paper today https://arxiv.org/abs/2005.03048 Exceptional Unification of Families and Forces Alfredo Aranda, Francisco J. de Anda, Stephen F. King [Submitted on 6 May 2020] This work considers the remarkable suggestion that the three families of quarks and...
  15. PGaccount

    A Physical Motivation for Supersymmetry

    How was supersymmetry discovered? 13:00 And what were the original motivations for it? Is there some kind of intuitive way to look at and work with the formulas? For instance, in the theory of differential forms, the scalar product of two 1-forms U and V is *(U ∧ *V) = UiVi. It is useful to...
  16. J

    What is the research focus of a Master at IHEP in High Energy Physics?

    i will enter the Institute Of High Energy Physic in Chinese Academy of Science on September in 2019 to start learning about particle physics. My research direction line in search for the decay of Higgs to Zgamma with CMS
  17. M

    Why does a SUSY Lagrangian only contain F and D terms?

    I'm reading a book on AdS/CFT by Ammon and Erdmenger and chapter 3 covers supersymmetry. This isn't my first look at SUSY but it's my first in depth look to really try to understand it, and when they talk about constructing a Lagrangian for ##\mathcal{N}=1## chiral superfields they write the...
  18. T

    B What's the status of supersymmetry

    So far no signs of supersymmetry has been found though there are theoretical support for it. Is supersymmetry still possible or has it been proven wrong?
  19. V

    B Supersymmetry Purpose: Explanation & Purpose

    Can someone give me an explanation telling me the actual purpose of supersymmetry and what it’s meant to show or predict or solve?
  20. wolram

    B Is Super Symmetry Dead? | Forbes

    Super symmetry has lasted a long time and has been searched for with bigger and bigger colliders, And the particles seem to get more and more massive as time goes by, I'm no expert but it seems unlikely That thees super heavy particles exist...
  21. H

    A Supersymmetry and the EM Force

    (This is easy for you folks that know SUSY.) I know in SUSY the agent of the EM force is the photino (a spin 1/2 fermion). The EM force that we all learned about in JD Jackson (and the QED version in Sakurai) has the photon (a boson) as the agent of force. Is the SUSY version of E&M, and the QED...
  22. Demystifier

    A Is there a new loophole in the no-go theorem of supersymmetry?

    Can someone comment on https://arxiv.org/abs/1703.10188 ? If correct, it seems very important.
  23. K

    I Moriond EW 2017 results -- No supersymmetry

    52nd Rencontres de Moriond EW 2017 présidé par Lydia Iconomidou-Fayard (LAL), Jean Marie Frere (ULB Brussels) has released results based on 36 fb-1 data @ 13 TEV they compare predictions from SUSY i.e squarks gluinos stops etc, with SM all results consistent with SM 95% No supersymmetry...
  24. K

    I Mirror matter and supersymmetry

    there is considerable research interest in supersymmetry, both for string theory and particle physics.What would be the implications to physics if parity symmetry is a fundamental symmetry, and therefore mirror matter and mirror bosons exist? would this imply mirror matter has all same exact...
  25. M

    A Representation theory of supersymmetry

    I had heard of adinkras but didn't realize that they were meant to play this role. Nor did I realize that the representation theory of supersymmetry is mathematically underdeveloped.
  26. K

    I Decay of the Bs0 particle and supersymmetry

    14 February 2017: First single experiment observation of the decay Bs0→ μ+μ-. From discovery to precision measurement. [ Branching fraction Bs0→ μ+μ- = (2.8±0.6)x10-9 ; B0→ μ+μ- < 3.4x10-10 ] "“We love this decay because it is one of the most promising places to search for any new effects of...
  27. H

    A Are Neutralinos Considered Composite in Supersymmetric Models?

    In supersymmetric extensions of the standard model, the neutralinos and charginos (popular candidates for dark matter) are often included. However, it is known that these fermionic particles are linear combinations of supersymmetric bosinos (such as gauginos and higgsinos). Therefore, it seems...
  28. N

    A Does supersymmetry rule out asymptotic safety?

    If we find supersymmetry at the LHC, would this prove asymptotic safety in QG wrong? Here's the article https://arxiv.org/pdf/1508.07411v2.pdf
  29. Heisenberg1993

    A Real parameters and imaginary generators

    I was reading some lecture notes on super-symmetry (http://people.sissa.it/~bertmat/lect2.pdf, second page). It is stated that ". In order for all rotation and boost parameters to be real, one must take all the Ji and Ki to be imaginary". I didn't understand the link between the two. What does...
  30. hsdrop

    B Is Antimatter the Other Half of Particles in Supersymmetry?

    ok guys this should be a quick one... I hope lol In supersymmetry could the other have of the particles be antimatter ?? its looking like the same thing to me... but I could be very wrong. But if I am, why would I be wrong ?? thank you to anyone that takes the time to replay
  31. wolram

    B Is supersymmetry a part of string theory

    Is supersymmetry part of string theory or does it have a place in the standard model
  32. haushofer

    Insights General Relativity as a Gauge Theory - Comments

    haushofer submitted a new PF Insights post General Relativity as a Gauge Theory Continue reading the Original PF Insights Post.
  33. K

    I LHC run 2, does Supersymmetry worsen hierarchy fine tuning

    post-LHC run 2, does Supersymmetry worsen hierarchy fine tuning? according to what most theorists argument, the SM has a hierarchy fine tuning in the Higgs sector based on naturalness. The proposed solution to this problem is supersymmetry. post-LHC run 2, no SUSY partners and no hints of SUSY...
  34. K

    I Supersymmetry breaking and hidden sector

    in gauge mediated supersymmetry breaking, theories say there is a hidden sector that breaks its own symmetries and then communicates it to a messenger field, which then breaks SUSY. any specific details on the hidden sector and messenger field? i.e what kind of fermions and bosons make up the...
  35. K

    I 5 Higgs-like bosons -- natural supersymmetry required?

    MSSM and nMSSM require 5 higgs like bosons in addition to the 126 GEV the SM predicts. thus far LHC has not found any of them. what masses are predicted for Natural SUSY for these additional higgs and how much of a problem is it that the LHC has not found them? if natural SUSY is correct...
  36. Urs Schreiber

    Insights 11d Gravity From Just the Torsion Constraint - Comments

    Urs Schreiber submitted a new PF Insights post 11d Gravity From Just the Torsion Constraint Continue reading the Original PF Insights Post.
  37. S

    A N=2 Super Yang-Mills: Auxiliary Fields Question

    I was wondering since the Vector supermultiplet in N=2 SUSY can be built from a Chiral and a Vector supermultiplet from N=1, in order to make up the off-shell degrees of freedom, would you include the two auxiliary fields from the N=1 theory (traditionally F from the Chiral and D from the vector...
  38. Urs Schreiber

    Insights Why Supersymmetry? Because of Deligne's theorem - Comments

    Urs Schreiber submitted a new PF Insights post Why Supersymmetry? Because of Deligne's theorem. Continue reading the Original PF Insights Post.
  39. K

    A What would falsify supersymmetry? LHC Nightmare scenario

    The LHC nightmare scenario after 15 years of operation and 3000 fb-1 total integrated luminosity at 14 TEV, it only finds Higgs and nothing else. with LHC not finding any SUSY partners and LUX/Panda not finding any WIMPS, obviously SUSY can be adjusted to accommodate these null results...
  40. F

    A Invariance of Wess Zumino Action under SUSY

    Hi guys, I have a very basic question about the WZ model. I want to show that it is invariant under SUSY transformations. The action is \int{d^4 x} \partial^\mu \phi* \partial_\mu \phi +i\psi^† \bar{\sigma}^\mu \partial_\mu \psi The SUSY transformations are \delta\phi = \epsilon \psi ...
  41. zdroide

    B H boson is 125 GeV, super symmetry, multiverse not possible?

    What other theories this number make impossible or improbable. When final number was given I hear some older physicist saying for one " 40 years of works gone" second grinding "only 30 for me!" We are ask to follow establish science. Seem to me that lots of theories was built on other's ones and...
  42. S

    A Spontaneous breaking of supersymmetry

    Dear All I am studying spontaneous breaking of supersymmetry but i am confused about something. Why should the goldstone be a spin 1/2, why it is not a boson? I have read that this is due to supersymmetry is a fermionic symmetry but i am not convinced with this answer! Thank you
  43. S

    Exploring Supersymmetry: A Beginner's Guide to the Fundamental Theory

    Dear All Can anyone suggest me a book as a basic introduction to supersymmetry In fact i have Wess and West but i need other. Thank you
  44. P

    How Do Bilinears Connect to Killing Vectors and Differential Forms?

    What does it mean that a Killing vector and a total differential of a certain theory are related to bilinears? In other words, why would bilinears (e.g. of the forms ##<\gamma_0\epsilon, \gamma_5\gamma_{\mu}\epsilon>## and ##<\gamma_0\epsilon, \gamma_{\mu}\epsilon>## tell us anything about...
  45. S

    How to know which gauge transformation we should use?

    Spinors in $N=2, D=4$ supergravity can be simplified using gauge transformation and thus canonical spinors can be found. In the case of $N=2, D=4$ supergravity the gauge transformation Spin (3,1) is used. My question is how do we know which transformation can be used in a certain theory in order...
  46. S

    What does ##\delta F=0## mean?

    Links for [1] and [2] are below. Please have a look here section 12.6 [1]. It says here that Given the action of a supergravity theory, it is generally useful to search for solutions of the classical equations of motion. It is most useful to obtain solutions that can be interpreted as...
  47. K

    Run 2 initial LHC @13 TEV Supersymmetry results null

    what are ramifications of exclusions on SUSY gluino mass 1.8 TEV to MSSM and other SUSY-SM and higgs hirearchy?
  48. E

    Why do those two terms add here?

    When I was studying complex manifolds in a Freedman's SUGRA book, I ran across this. In a complex manifold, the metric is...
  49. E

    Why Complex Scalars in 4D Supersymmetric Theories?

    The scalar fields of supersymmetric theories in 4 spacetime dimensions are a set of complex fields (usually denoted by ##z^{\alpha}##). How can this be physically translated? More precisely, we know that in 5D, those scalars are real, so what is that makes them real here but complex there?
  50. Smattering

    Can supersymmetry be considered a falsifiable prediction?

    Hello everybody, Recently, I read this interview with Edward Witten where he claims that supersymmetry is a falsifiable prediction of string theory. But then again, I remember interviews with proponents of supersymmetry where they were asked whether the inability to find any hints of SUSY in...