What is Susy: Definition and 115 Discussions

Susy is a feminine given name, sometimes a short form (hypocorism) of Susan, Susanne, Susannah, etc.

Susy may refer to:

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  1. arivero

    I Lecture notes on SUSY using finite matrix as example?

    As you know, a lot of SUSY examples, particularly from Witten's "SUSY QM", pivot on the factorisation trick: produce two hamiltonians $$H_0=AA^+, H_1=A^+A$$ and see they have the same eigenvalues except for ceros. The proof usually goes by: let ##\Psi## be an eigenvector of ##H_0##, consider...
  2. G

    I Antimatter Susy Sparticles: Exploring Symmetry

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

    I Is SUSY still a possibility with current EDM limits and energy constraints?

    Hello! I am really not an expert in this so please correct me if I say something stupid. I read a few articles (e.g. https://journals.aps.org/rmp/pdf/10.1103/RevModPhys.90.025008) in which there are presented the implications of low energy physics on high energy physics. In the electric dipole...
  4. A

    Simplified SUSY models with different mixing cases

    Hi Probably a bit technical, but here it is. I am trying to construct some simplfied SUSY models (that is, you only tune the masses of the core process, while all the rest are decoupled), and I would like to play with different mixing scenarios for the neutralino and charginos, so to get a...
  5. Z

    Commutation relations in SUSY

    I hope I put this in the correct section of this forum, I apologize if I didn't. Homework Statement :[/B] It is well known that the generators $$ Q_\alpha = \frac{\partial}{\partial \theta^\alpha} - i \sigma^\mu_{\alpha \dot \beta} \bar{\theta}^\dot{\beta} \partial_\mu $$ and $$...
  6. 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...
  7. ohwilleke

    I Is there new LHC data on coupling constant running?

    Question Has the LHC released any papers or reports on the observed running of any of the three Standard Model coupling constants with energy scale from either Run-1 or Run-2 data (or both data sets)? Last time I looked I couldn't find any data As of January 2014, I had not locate any papers...
  8. MrRobotoToo

    I SUSY and GUTs all but eliminated by latest ACME experiment

    I'm surprised no one has posted about this yet, so I guess I'll take it upon myself to post the link, even though I have no real expertise on the subject. The ACME collaboration had the results of their latest measurement of the electron's EDM published in Nature today. They place an upper...
  9. ohwilleke

    I BSM conference '17 notes

    This 54 page review article from a September 2017 conference in Portugal is a good starting point for people wanting an overall summary of the state of BSM physics theories that is reasonably up to date, and may suggest questions about specific theories that deserve more attention in this forum...
  10. Sandeep T S

    Any textbooks on LQT, SUSY and/or QG?

    Can anyone suggest any text, which I can start work on LQT, STRING THEORY, QUANTUM GRAVITY.
  11. B

    B LHC Constrains on Compactified M-theory SUSY particles

    I just finished Gordon Kane superb book "String Theory and the Real World" in one sitting. It answered most of my current questions about the field. I need some hard data. He mentioned: "More generally, where did the predictions for superpartner masses come from? Until recently there were no...
  12. ohwilleke

    I Is there a fine structure constant running anomaly?

    Background The chart above, via Lubos Motl's blog which is standard in any textbook talking about supersymmetry, illustrates the running of the the inverse of the Standard Model (SM) and Minimal Supersymmetric Model (MSSM) coupling constants with energy scale for the electromagnetic force...
  13. Ken Gallock

    Clifford algebra in higher dimensions

    Homework Statement Consider gamma matrices ##\gamma^0, \gamma^1, \gamma^2, \gamma^3## in 4-dimension. These gamma matrices satisfy the anti-commutation relation $$ \{ \gamma^\mu , \gamma^\nu \}=2\eta^{\mu \nu}.~~~(\eta^{\mu\nu}=diag(+1,-1,-1,-1)) $$ Define ##\Gamma^{0\pm}, \Gamma^{1\pm}## as...
  14. L

    I Fermions Bosons vertices in SM - but no SUSY

    In the Standard Model fermions interact via exchanges of massless (virtual) spin-1 particles. Fermions are turned into a boson. How is that different from the SUSY transformation that turns fermions into bosons?
  15. Chip

    A Unifying String Theory and SuSy

    It seems that the latest data out of CERN suggest a mass of the Higgs Boson that is smack in the middle of what would be suggested by parallel universes/string theory and SuSy. Do you think Edward Whitten, Savas Dimopoulos, and probably others could get together in a room to unify these two...
  16. K

    A No SUSY at ICHEP, Limits on gluino masses now up 1.9 TeV

    pdf link here https://indico.cern.ch/event/432527/contributions/1071444/attachments/1320402/1979943/Miller_ICHEP2016_AllHadronicSUSY_4Aug2016.pdf Given that they found no SUSY gluinos squarks with this years data set of 18-19 fb-1 + 2-4 fb-1 from last year what are the prospects for natural...
  17. K

    A If LHC reports no SUSY by Aug 2016 data set

    according to blogger Tommaso Dorigo the LHC "What to expect for ICHEP I believe that if the machine keeps delivering at this pace, by mid-July CMS and ATLAS could have in their hands some 10 inverse femtobarns of 13-TeV collisions. Those data, three to four times larger in size that what was...
  18. K

    A Implications of a new 17 Mev vector boson on Higgs, SUSY

    regarding this paper Evidence for a Protophobic Fifth Force from 8Be Nuclear Transitions Jonathan L. Feng, Bartosz Fornal, Iftah Galon, Susan Gardner, Jordan Smolinsky, Tim M. P. Tait, Philip Tanedo (Submitted on 25 Apr 2016) Recently a 6.8σ anomaly has been reported in the opening angle and...
  19. 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 ...
  20. wolram

    Is SUSY the next big step in cosmology

    https://www.sciencedaily.com/releases/2012/01/120111135928.htm When will SUSY detection be, 10yrs 30yrs what will SUSY tell us about cosmology. A better understanding of the universe will be the outgrowth of the discovery of the Higgs boson, according to a team of University of Oklahoma...
  21. S

    Susy algebra trivial question

    Dear All Am trying to study supersymmetry algebra. We start by constructing the graded poincare algebra by considering the direct sum of the ordinary Poincare algebra L0 with a subspace L1 spanned by the spinor generators Qa where a runs from 1 to 4 ( L1 is not a lie algebra ). So now we have...
  22. D

    A Constructing massive N=1 SUSY Multiplets

    This isn't really a homework question because our professor has declined to set any exercises or homework (or publish any notes at all) much to the class's chagrin. He claims that we should go through what we do in the lectures and correct all the mistakes he makes on the board (since he refuses...
  23. N

    Example of Susy QM and its partition function

    I am reading an article by Tachikawa on the Nekrasov partition function ("A review on instanton counting and W-algebras"). The article is meant to be pedagogical but I have some trouble with what is supposed to be "baby" examples. The first one involves susy QM on \mathbb{C}^2 . He says the...
  24. N

    A few simple questions about Susy

    The Wikipedia entry on susy says "Typically the number of copies of a supersymmetry is a power of 2, i.e. 1, 2, 4, 8. In four dimensions, a spinor has four degrees of freedom and thus the minimal number of supersymmetry generators is four in four dimensions and having eight copies of...
  25. atboria

    Recommended books/papers in SUSY

    Hey everyone! I just wanted some advice in some user-friendly bibliography in SUSY (I have QFT background and GR too, I don't know if this is relevant but whatever...). My intention is to learn it on my own, maybe I can ask some questions to a professor. Thank you in before!
  26. P

    What is the current status of susy and string theory?

    I heard that the LHC was supposed to do some testing on supersymmetry but i didn't hear anything from them and is string theory still possible or not.
  27. K

    Scientific implications of latest LHC SUSY beauty quark

    http://news.discovery.com/space/lhc-keeps-bruising-difficult-to-kill-supersymmetry-150727.htm LHC Keeps Bruising 'Difficult to Kill' Supersymmetry Previous attempts at measuring the beauty quark's rare transformation into a so-called "up quark" had yielded conflicting results. That prompted...
  28. H

    Reps of the SUSY algebra: raising and lowering operators

    I'm reading Alvarez-Gaume review on Seiberg-Witten theory: http://arxiv.org/abs/hep-th/9701069. Around page 23 you can find the following claim: "This is a Clifford algebra with 2N generators and has a 2N-dimensional representation. From the point of view of the angular momentum algebra, a^I...
  29. T

    Solving Trivial SUSY Questions: Adel Bidal Introduction to SUSY

    Im reading Adel Bidal Introduction to SUSY. It is all pretty much clearly deduced from the asumptions, but I don't understand the asumptions... In particular, I am talking about the Qs commutation: 1 with Ps: why are they assumed to be 0. 2 with Ms: why are the proportional of Qs but not of Ms...
  30. Jimster41

    If SUSY is found, is String Theory the expected why?

    As I understand it the proposed SUSY model is based on an "expectation of symmetry", which also happens to nicely solve specific problems with the SM. If the LHC does find evidence of SUSY structures - is string theory a candidate for a fundamental theory that would "explain the harmony" of the...
  31. O

    SUSY Leptons & Quarks: Exploring Their Existence in Nature

    If susy really exist in nature, why does it not exist between leptons or quarks and gauge bosons such as photons, weak currents or gluons in the standard model?
  32. Jesus

    SUSY N=1 masless supermultiplet

    In the massless case of N=1 simple supersimetry, the states are labeled by the helicity λ and the four-momentum. In this case we have two states in the supermultiplet plus CPT conjugates: |pμ, ± λ> and |pμ, ± (λ-½)> Then there is a λ= {0, ½} supermultiplet (where for example a quark with λ=½...
  33. S

    Novice's Question on Spontaneous SUSY Breaking & Goldstinos

    I'm a novice in SUSY and I'v got a question concerning spontaneous supersymmetry breaking and goldstinos. In Martin's review on page 68 there is a proof of a statement about existence of massless particle when one of ##F_i##'s or ##D_a##'s VEV is not zero. The thing I don't get is why vector...
  34. E

    Link between CP violation and supersymmetry?

    I have been looking in SUSY and have seen that the CP violation of B mesons into two muons is one of the key facts that has cast further doubt over SUSY. I don t really understand how the CP violation of B mesons is a sign of SUSY issues, so if you are able to clear this up for me that would be...
  35. arivero

    BLRPV, a new SUSY, it seems.

    Interesting paper: http://arxiv.org/abs/1409.5438 Simultaneous B and L Violation: New Signatures from RPV-SUSY The Superpotential has terms UDD and QLD. Does it mean that a Diquark can decay to an antiquark, and a Meson can decay to a Lepton? I am not sure of the second point. The paper show...
  36. L

    Gauged & Ungauged SUSY & SUGRA: Exploring the Differences

    Hi, I'm curious as to the differences between gauged and ungauged SUSY and gauged and ungauged SUGRA. Perhaps I can break down my problems into the following few questions: (i) I understand that to go from SUSY to SUGRA, one must make the supersymmetry local. What does this mean? I've read...
  37. Safinaz

    Susy and symmetry breaking

    Hi guys, I have a question about symmetry breaking in Susy, I hope it won't be so naive that I just started to study supersymmetry .. The question is that there are two Higgs doublets in Susy, H_u and H_d, how these two doublets first break supersymmetry at high energy scale and then make...
  38. ChrisVer

    Ques. F Term SuSy Breaking -Bailin & Love

    I have a problem understanding the attached part of the book... Specifically how they derived this result for the Fs... For example I'll try to write: F_{1}^{\dagger}= - \frac{\partial W(Φ_{1},Φ_{2},Φ_{3})}{\partial Φ_{1}}|_{Φ_{1}=φ_{1}} If I do that for the O'Raifeartaigh superpotential I'll...
  39. ChrisVer

    Proving SuSy Algebra Fulfillment for Qa & Qb Commutation

    So I'm trying to show that one choice of representation for the SuSy generators fulfills the SuSy algebra... (one of which is \left\{ Q_{a},\bar{Q_{\dot{b}}} \right\}= 2 \sigma^{\mu}_{a\dot{b}} p_{\mu})... For Q_{a}= \partial_{a} - i σ^{μ}_{a\dot{β}} \bar{θ^{\dot{β}}} \partial_{\mu}...
  40. K

    Representation of SUSY Algebra

    I have some questions about representations of SUSY algebra. (1) Take ##N=1## as an example. Massive supermultiplet can be constructed in this way: $$|\Omega>\\ Q_1^\dagger|\Omega>, Q_2^\dagger|\Omega>\\ Q_1^\dagger Q_2^\dagger|\Omega>$$ I understand the z-components ##s_z## of the last...
  41. N

    Understanding BPS States and Their Relation to Supersymmetry Generators

    A quick and simple question: one always talks about BPS states annihilating half the supercharges. What does that mean exactly? For example, in a pedagogical article by Alvarez-Gaumé and Hassan they give the anticommutator of one set of supercharges to be \{b_\alpha, b_\beta^\dagger \} =...
  42. Safinaz

    Why in SUSY we tend to use 2- components

    Hi all, why in SUSY we tend to use 2- components Weyl spinor field not the ordinary Dirac filed .. Regards, Safinaz
  43. marcus

    AsymSafe QG rejects SUSY & extra dims (Donà Eichhorn Percacci)

    Percacci and friends have found incompatibility between Asymptotically Safe quantum gravity on the one hand and, on the other, extensions of the Standard Model which involve supersymmetry and/or extra dimensions. If evidence for supersymmetry or extra dimensions ever shows up that would tend...
  44. L

    On SUSY irreps: eigenvalues of Pauli-Lubanski operator?

    Hi everyone, Just an easy question that came to my mind while studying basics of SUSY. Consider in N=1, D=4 a massive clifford vacuum |m,s,s_3\rangle, and for cconcreteness take its spin to be s=1/2. Now, acting with the four supercharges on both the |m,1/2,1/2\rangle and |m,1/2,-1/2\rangle...
  45. K

    What is the expression of N=2 SUSY transformation

    I have checked many textbooks and papers on SUSY and it seems that none of them mentions anything about the infinitesimal susy transformation on component fields in the case N\neq 1. So I am wondering what does it looks like, say for N=2 vector multiplet? Another related question is, do we need...
  46. K

    Infinitesimal SUSY transformation of SYM lagrangian

    I tried to verify that the SYM lagrangian is invariant under SUSY transformation, but it turned out there is a term that doesn't vanish. The SYM lagrangian is: \mathscr{L}_{SYM}=-\frac{1}{4}F^{a\mu\nu}F^a_{\mu\nu}+i\lambda^{\dagger a}\bar{\sigma}^\mu D_\mu \lambda^a+\frac{1}{2}D^a D^a the...
  47. K

    Questions about N=1 SUSY and Magnetic Monopoles

    For N=1 SUSY, the SUSY algebra is closed as long as Bianchi identity \epsilon^{\mu\nu\rho\sigma}D_\nu F^a_{\rho\sigma}=0 is valid, that is [\delta_{\epsilon_1},\delta_{\epsilon_2}] \propto P . What if there is magnetic monopole when Bianchi identity doesn't hold? When N=2, there is central...
  48. S

    Supergravity = local SUSY or gravity mediation?

    Hi, in some texts, the term supergravity refers to locallized supersymmetry but most of the times, I have the impression that it refers to gravity mediated supersymmetry breaking (i.e. higher dimensional terms in the kahler- and superpotential that are suppressed by powers of the Planck...
  49. C

    Usefulness of SUSY models when it cant exist at non-zero temperatures

    Unlike other symmetries (like electroweak symmetry), SUSY is spontaneously broken at any non-zero temperature due to some variation of the fact that the boundary conditions on bosons and fermions in thermal QFT are different. If this is the case, what is the rationale for considering SUSY...
  50. S

    Susy preserving branes and equation of motion

    Hello, I've thought about it a few times and this question interests me. If a brane (M2 in my case) in euclidean signature preserves some supersymmetry, does it automatically solve the equation of motion? In order to be more precise here is what I mean: Take 11D SUGRA with an AdS_4xS^7...