Susy Definition and 104 Threads

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...

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

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...

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...

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...

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...

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

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...

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...

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...

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?

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...

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...

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...

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...

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 ...

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...

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...

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...

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...

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...

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!

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.

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...

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...

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...

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...

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?

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...

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...

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...

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...

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...

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...

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...

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}...

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 \} =...

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

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...

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...

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...

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...

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...

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...

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...

Last year I was studying supersymmetry and since them I'm regularly thinking to one question for which I don't have answer: when one looks at the susy algebra with N generators, one sees that there is a U(N) R-symmetry. But for N=4, the group is in fact SU(4). To explain this, one generally...

I've been studying, just for pleasure, but studying in the end, a lot about QFT and its prerrequisites reaching some not so bad understanding of the Standard Model. I know that I still have to fill a lot of gaps, but nevertheless, I am looking for some new topic to start reading (while I fill...

Is SUSY theory "necessary" at this point? I have a question: http://www.scientificamerican.com/article.cfm?id=beautiful-theory-collides Based on the presumed energy state of the newly found Higgs Boson, is SUSY theory even necessary or beneficial in terms of explaining particle physics...

Hi, I have a question about non-relativistic SUSY, see e.g. "non-relativistic SUSY" by Clark and Love. The supersymmetric Galilei algebra with central extension M can easily be obtained from the N=1 Super Poincaré algebra by an Inonu-Wigner contraction. In this proces, SUSY and spacetime...

Hello, How could SUSY provides a candidate to dark matter since it would only appear only above the TeV scale? The galaxies' environments is at such energies? Thanks