A postulated symmetry between bosonic and fermionic fields in quantum field theories and string theories.

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Are Axinos an attractive candidate for Dark Matter and why?

Out of the SUSY DM candidates Gravitinos and Neutralinos are considered more likely than Axinos however I cannot find much on these. NB: Note the difference between axions and axinos.
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How does gauge invariance protect the SM gauge boson masses in SUSY from divergent radiative corrections?

The W and Z gauge bosons receive radiative corrections in loop from the heavy SUSY scalars. There is an argument using gauge invariance which explains how the masses remains protected. I am not able ...
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378 views

What's the Coulomb Branch and why is it important?

I'm studying the introduction of flavour degrees of freedom in the AdS/CFT correspondence and now I'm supposed to calculate the mass spectrum of mesons in the Coulomb branch. I have searched the ...
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What are ${\cal N}=4$ and ${\cal N}=2$ theories?

I often hear of ${\cal N}=4$ and ${\cal N}=2$ theories. For example, in the talk. What are ${\cal N}=4$ and ${\cal N}=2$ theories? Are there some ${\cal N}=k$ theory, $k \neq 4, 2$?
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58 views

Why is the infinitesimal SUSY variation generated by the sum of a left- and right-chiral generator

I was wondering why in many (all? e.g.https://arxiv.org/abs/hep-ph/9709356) resources on N=1 SUSY the variation of a field in the simplest free susy model is defined as $$\delta_\epsilon \phi = (\...
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236 views

Intuition for S-duality

first of all, I need to confess my ignorance with respect to any physics since I'm a mathematician. I'm interested in the physical intuition of the Langlands program, therefore I need to understand ...
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711 views

S-Matrix in $\mathcal{N}=4$ Super-Yang Mills

This is a general question, but what is meant when people refer to the S-Matrix of $\mathcal{N}=4$ Super Yang Mills? The way I understood it is the S-Matrix is only well defined for theories with a ...
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170 views

With the LHC about to restart as max energy, are there absolutely no hints or tantalizing signs of Supersymmetry in previous data?

Over the last couple of years I've seen several articles talk about hints or bumps in the data that might point to Supersymmetry. An article in NewScientist from Summer 2012 discussed the discovery of ...
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Detecting supersymmetry

What would scientists in particle colliders look for as evidence of supersymmetry?
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199 views

Can a superpartner be less massive than its SM counterpart?

Theoretically, can a superpartner be less massive than its standard model counterpart? I realize there are experimental constraints.
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87 views

How to find SUSY with near-degenerate masses?

In SUSY models, you can have the case that sparticles and their decay products have near-degenerate masses. For example $$ m(\tilde \chi^\pm_1) - m(\tilde \chi^0_1) < 1\,\mathrm{GeV}$$ Then in ...
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167 views

What does the discovery of the Higgs boson mean for SUSY? [duplicate]

I've seen many differing opinions on how the discovery of the Higgs boson (specifically due to its mass) has effected theories of Super Symmetry, but all seem fairly biased. I'm wondering if someone ...
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516 views

Sparticles: Relationship to supersymmetry and dark matter?

I was attempting to read this paper after watching a show with Brian Greene. As I understand it, sparticles are a prediction of supersymetry, so I was wondering: Wouldn't the discovery of ...
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205 views

Why are the third generation superpartners lighter than the other sfermions in MSUGRA

In the MSUGRA breaking scenario, the stop particle typically appears at energies reachable at the LHC. Other sfermions, notably the partners of up, down, strange and charm are assumed to be degenerate ...
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1answer
50 views

To which type of particles gauginos are supposed to couple?

I wonder about to which type of particles gauginos couple in general. I admit my knowledge in supersymmetry is very limited. Let's take an example: The photino. If it behaved similar to the photon, it ...
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21 views

Supersymmetry particles in cosmic ray showers

Antimatter was first discovered in cosmic ray debris. Why haven't we found the heavy supersymmetry particles in cosmic ray debris?
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Superfields and the Inconsistency of regularization by dimensional reduction

Question: How can you show the inconsistency of regularization by dimensional reduction in the $\mathcal{N}=1$ superfield approach (without reducing to components)? Background and some references: ...
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35 views

Mass dimension and Abelian super-gauge transformation

A vector superfield is defined by postulating an invariance under a linear transformation in the space of vector superfields: $V \longrightarrow V + i\Lambda - i\Lambda^{\dagger}$ where $i\Lambda - ...
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51 views

Superfields in 2D SUSY

Many textbooks present expressions for superfields in $4$ dimensions. For my current project, I have to find out how things work in $2$ dimensions. Let me summarise in short what we know about $4$d (...
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69 views

What is the difference between worldsheet supersymmetry and spacetime supersymmetry?

What is the difference between worldsheet supersymmetry and spacetime supersymmetry? For worldline formulation of fermions quantum mechanics, there is a supersymmetry. But the corresponding spacetime ...
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1answer
37 views

How can one determine whether two given Hamiltonians are supersymmetric partners?

Given two Hamiltonians in a general form of second order differential equations, how do I find out if they are SUSY partners or not? Given the factorisation of a Hamiltonian in the form of $a^\dagger ...
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1answer
110 views

A question from A. Zee's book

On page 463, it writes in eq. (3) $$4H=\Sigma_\alpha(Q_\alpha Q^\dagger_\alpha+Q^\dagger_\alpha Q_\alpha).\tag 3$$ And then it writes that this is followed by eq.(4) as $$\langle S| H|S\rangle=\frac{...
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1answer
46 views

Should the complex conjugate of a derivative of a Grassmann number include a sign?

Take a real Grassmann variable, by which I mean $\theta=\theta^*$. We have $$\int d\theta~ \theta =1,\qquad \frac{\partial}{\partial\theta}\theta=1$$ If I define the conjugation of Grassmann ...
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31 views

Second derivative of Kahler potential [closed]

Does the following second covariant (in terms of Kahler geometry) derivative of Kahler potential vanish? \begin{equation} K_{ij}\equiv\nabla_i\nabla_j K=0, \end{equation} \begin{equation} K_{i^*j^*}\...
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1answer
79 views

Derivation in Modern Supersymmetry by Terning

I am trying to do some calculations from Modern Supersymmetry by Terning and I am stuck on how he derived a particular term. Specifically, I am looking at 2.67 on page 27. My current work is below. $$...
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37 views

Which supersymmetry principles make the axio-dilaton field in F-theory holomorphic?

I am following the lecture notes on F-theory by T. Weigand . On page 7 he states that when considering F-theory as the strong coupling limit of type IIB orientifolds with D-branes, the axio-dilaton ...
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31 views

Anti-commutator relation of supercharges

Reading mutiple references on SUSY (e.g. Baer and Tata's Weak Scale SUSY and A SUSY Primer by S.P. Martin, arXiv:hep-ph/9709356), there seems to be different anti-commutation relation conventions for ...
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The super Grassmannian $G_{2|2}(4|4)$

In the paper, the super Grassmannian $G_{2|2}(4|4)$ is defined by (12)--(18). An element of $G_{2|2}(4|4)$ can be written as a $(2 | 2) \times (4 | 4)$ matrix of full rank modulo the left action by ...
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43 views

Notation of supermatrices

I am trying to understand supermatrices. First I want to know the notation of supermatrices. In the paper, it is mentioned $(2|4|2) \times (2|2)$ supermatrices. What are $(2|4|2) \times (2|2)$ ...
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118 views

What is the Superpartner of a glass? [closed]

A little context: This summer I visited Switzerland and had the chance to tour CERN. While there, I saw through an open door this question written at the top of a chalkboard in John Ellis's office. I ...
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1answer
280 views

How does a supersymmetry transformation relate bosons to fermions?

A superfield is defined as a function of of a spacetime coordinate and two spinor coordinates, $\Phi (x, \theta, \theta^*)$. A supersymmetric transformation is then generated by the operator $\...
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91 views

Vacuum energy and supersymmetry [closed]

Let us assume that dark energy is the energy of the vacuum. The density of this vacuum energy has been measured to be about $10^{-26}$ $kg/m^3$. Using the Compton wavelength formula, $\lambda=h/mc$, ...
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73 views

How do we know if a Killing Spinor is Time-like or Null?

How to know whether a Killing spinor orbit is time-like or null? This is present in a paper like this 29/39 here. I'm not asking for a technical answer, just a logical cliche answer chit-chat answer. ...
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1answer
91 views

${\cal N}=4$ SYM in terms of ${\cal N}=1$: The $SO(6)$ in the Yukawa term

I'm trying to write ${\cal N}=4$ SYM in terms of ${\cal N}=1$ superfields. I have the Lagrangian $$\mathcal{L}=\frac{1}{16 k} \int d^2 \sigma \text{Tr} \big[W^a W_a\big]+c.c+\int d^4\theta \text{Tr}\...
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27 views

How to find curved superspace vielbein and connection?

Need help with finding total curved superspace vielbein and connection in terms of SUGRA multiplet components (graviton, gravitino, auxiliary real vector and complex scalar). In Wess and Bagger ...
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“Constant Fermion”

I was talking to a professor in my institution which works in Lorentz Violation of various QF theories. While we talk about a SUSY lagrangian, I asked him if we could have a fermion acquiring VEV and ...
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85 views

Why is Seiberg duality called an electromagnetic duality?

An electromagnetic duality is a duality that maps electric to magnetic degrees of freedom of two distinct theories. Apart from source-less Maxwell electrodynamics, other theories require magnetic ...
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16 views

How relevant are non-minimal Kahler potentials in supergravities?

Does it make sense to consider non-minimal Kahler potential of the form $K\sim|\phi|^4$? Or, to slightly rephrase the question, can we altogether ignore scalar kinetic terms with coefficients ...
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1answer
59 views

D-branes conserving only half of the supersymmetries

Concerning D-branes as BPS states from T-duality. In D-Branes by Johnson (and other sources) I find the following statement (p.196): "Only the total [supersymmetric] charge of $Q_a+\tilde{Q}_a$ of ...
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39 views

What is a “Scalar Manifold”?

I'm trying to understand a recent paper working within the context of $\mathcal{N}=8$ gauged supergravity with gauge group $\rm{SO}(6)$. There are a number of statements along the lines of: "...the ...
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1answer
42 views

Confusion about supergravity multiplet

I have a bit of confusion with the following consideration. Generally, to impose some BPS condition (i.e. to check if some multiplet preserves some SUSY charges) one imposes to zero the SUSY ...
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1answer
40 views

Supersymmetry algebra convention?

As derived for instance in this review (page 23-24), the supersymmetry algebra involving grassmann valued generators $Q_\alpha$ and ${\bar Q}_{\dot\alpha}$ is given by: $$[Q_\alpha,M^{\mu\nu}]=(\...
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Supersymmetrizing bosonic actions at higher orders

Given only the bosonic terms of a supersymmetric action, using a knowledge of the (local) supersymmetry transformations, is there a systematic way of reconstructing the fermionic terms? More generally,...
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1answer
88 views

Supersymmetry and grand unification

I came across this diagram in my introductory particle physics class. Given the fact that SUSY can make the plot look suspiciously nice, what can we do with it? Also, electromagnetism has been ...
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23 views

Equivariance Relation - Superconformal Hypermultiplets

I'm concerned with equation 2.24 of http://arxiv.org/abs/1601.00482 The superconformal hypermultiplets in this paper have a conic hyperkahler target manifold and the authors want to gauge some ...
3
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132 views

What is the motivation for using Calabi-Yau manifolds in string theory?

I have just begin to study Calabi-Yau compactification. Looking in many book I found that, if we start with a critical superstring theory in $D=10$, we are in search of a compact $D=6$ Calabi-Yau ...
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196 views

Showing closure of the SUSY algebra of a free abelian gauge multiplet

Given the complete supersymmetric lagrangian of a free abelian gauge multiplet $$ \mathcal{L} = -\frac{1}{4} F_{\mu\nu} F^{\mu\nu} + i \bar{\lambda} \bar{\sigma}^\mu \partial_\mu \lambda + \frac{1}{2} ...
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Supersymmetric background and fermion variations

I'm trying to understand some basic questions about supersymmetric theories in curved backgrounds and supergravity. If I understand it correctly, there's a condition for a background to preserve SUSY, ...
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357 views

Apparent failure of SUSY nonrenormalization theorem

I am having trouble reconciling two pieces of information. Consider supersymmetric QED, i.e. a supersymmetric U(1) gauge theory with two chiral superfields of opposite charges, $h$ and $\hat{h}$. The ...
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79 views

What is the Lorentz group representation for a general spin?

Setup, as I understand things so far: One way to think about where the spin of a quantum field comes from is that it is a consequence of the ways that different types of fields transform under ...