Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [supersymmetry]

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

1
vote
0answers
18 views

Checking modularity-like transformation property

Assume $M$ is a 4 manifold. Let $Z_v$ be partition function of fixed magnetic flux $v$ with all instanton configuration summed over where $v\in H^2(M,Z/nZ)$. $\tau$ denotes complex parameter on upper ...
0
votes
0answers
24 views

Where can I find the detailed calculation for the mass of the lights Higgs boson in MSSM?

can somebody mention where the mass of the lights Higgs boson in MSSM (minimal supersymmetric standard model) is discussed? I need a detailed and thorough explanation of the subject mater. I ...
0
votes
1answer
33 views

What does $\mathcal{N}$ refer to in Gauge theories?

Context: I am a second-year (undergraduate) physics major applying for a summer research position. The investigator is working on Quiver Gauge Theories and in response to my inquiry email he told me ...
1
vote
1answer
34 views

Superparticle in Background Gauge Fields

A simple model for a superparticle is $$L=m\int dt\left(\dot{x}^{2}-\frac{i}{2}\psi\dot{\psi}\right)$$ with SUSY algebra $\delta x=-i\epsilon\psi$ and $\delta\psi=-\epsilon\dot{x}$, where $\...
2
votes
0answers
18 views

SUSY variation Wess-Zumino

I'm following John Terning book on Supersymmetry and in particular I'm trying to check the susy variations of the Wess-Zumino model given by $\mathcal{L}_s = \partial^\mu \phi^* \partial_\mu \psi \,...
0
votes
0answers
21 views

Differentiating D3 brane worldvolume theories with NS5 brane and NS5 antibrane boundary conditions

In 'Supersymmetric Boundary Conditions in N=4 Super Yang-Mills Theory', Gaiotto and Witten derive boundary conditions for the worldvolume theory of the D3 brane. In particular the boundary conditions (...
3
votes
1answer
58 views

Intuition for the supertrace identity in supersymmetry

In pretty much every introductory book/lecture notes I've come across, one finds the expression for the mass matrices for scalars, fermions and vector bosons for a generic Lagrangian, and simply ...
0
votes
1answer
55 views

Transformation algebra of supersymmetry transformation

Given supersmmetry transformation: $$δX^\mu = i\barξψ^\mu.δψ^\mu = ξγ^a(∂_aX^\mu-\frac i2\barχ_a ψ^\mu). δχ_a = 2 D_aξ.$$ How to calculate the transformation algebra of $X^\mu$ and $\psi^\mu$? ...
0
votes
0answers
159 views

Supersymmetry and reparametrization invariance of superstring action

Section $4.3.5$ Superstring action and its symmetries, Page$229$ Superstring theory by Green, Schwarz and Witten. $S_1=-\frac1{2π} ∫d^2σ\ eh^{αβ}∂_αX^μ∂_βX_μ.\quad S_2=\frac i{2π}∫d^2σ\ e\barψ^μρ^α∇...
4
votes
1answer
112 views

Constrained Hamiltonian systems: spin 1/2 particle

I am trying to apply the Constrained Hamiltonian Systems theory on relativistic particles. For what concerns the scalar particle there is no issue. Indeed, I have the action \begin{equation} S=-m\int ...
0
votes
1answer
53 views

SUSY vacuum has 0 energy?

This is related to Modern Supersymmetry: Dynamics and Duality by Terning. Consider $N=1$ SUSY. $\{Q_a,\bar{Q}_{\dot{a}}\}=2\sigma_{a\dot{a}}^\mu P_\mu$. Sum over $a=\dot{a}=1,2$ and this yields $4P^...
0
votes
0answers
42 views

A few basic questions on SUSY algebra

Consider SUSY generator taking the form {$Q_a^A,Q_{\dot{b}B}$}$=\delta_{a\dot{b}}\delta^A_B$ and {$Q_a^A,Q^B_b$}={$\bar{Q}_{\dot{a}A},\bar{Q}_{\dot{b} B}$}=0 where $a,b$ label spinor index and $A,B$ ...
2
votes
1answer
77 views

${\cal N} = 1$ SUSY Non-renormalization theorem

In Ref. 1, on Page 53, the ${\cal N} = 1$ SUSY non-renormalization theorem is derived. One first specifies the symmetries of the general ${\cal N} = 1$ SUSY action in the superspace formalism, and ...
0
votes
0answers
39 views

Symmetries on String theory

Recently I was watching and reading about String theory, M-theory and the supersymmetry, when I remembered one question that I had while reading 'The Elegant Universe' by Brian Greene that is: why do ...
1
vote
0answers
34 views

Gauge fixing while preserving supersymmetry

In supersymmetric gauge theories, the vector potential is a part of a vector supermultiplet which is represented by a real superfield $V$. Expanded out in components, the Lagrangian for such a field ...
2
votes
1answer
57 views

Supercharge transformation rules

Consider ${\cal N}=2$ supersymmetry with $SU(2)$ global symmetry group. Then both supercharges $Q_{ai},\bar{Q}_{\dot{a}\dot{j}}$ transform by 2 dimensional representation of $SU(2)$. Denote $SU(2)_I$ ...
1
vote
0answers
33 views

Partition function computation on a Riemannian Manifold

This discussion comes from Chapter 10, Mirror Symmetry. I am given a Riemannian manifold $M$, and a classical (Euclidean) theory: $$(1)\quad S_E={\int}_0^\beta d\tau\space\Bigl(\frac{1}{2}g_{ij}{\dot{...
1
vote
0answers
20 views

Vandermonde determinant factor in supersymmetric gauge localisation computation

I am trying to learn supersymmetric localisation computation in which the path integral of a supersymmetric gauge theory (placed on a sphere) can be localised exactly to a BPS configuration ...
0
votes
0answers
16 views

Superstrings and supermembranes withouth the maximal spin constraint

Can supermembranes exist in higher dimensional superspaces if we admit higher spin fields?
1
vote
0answers
29 views

Does the vanishing of the one loop beta function imply no running to all orders?

This question sounds ridiculous, but bear with me. I am having a hard time reconciling the following two facts: Classical global symmetries can become anomalous upon quantization, and the anomalous ...
-1
votes
1answer
51 views

Is possible to replace the photon as a force carrier of electromagnetic force with a sfermion-fermion relation pair model?

force carriers or messenger particles or intermediate particles are particles that give rise to forces between other particles. I read that A field’s spin is determined by how it transform if you ...
1
vote
1answer
45 views

Supersymmetry: spin of the superpartners

I'm currently working on my master thesis, and I need to know a bit of supersymmetry. I have been looking the theory and I have a basic knowledge about it. I have a problem with understanding the ...
1
vote
2answers
128 views

Is there such a thing as an anti-boson?

Can there be an anti-boson that when interacting with normal bosons, creates matter, like when anti-matter creates energy when interacting with matter? I know that anti-particles can be considered ...
2
votes
1answer
54 views

Supersymmetry transformation: why does the Lagrangian transform as total derivative?

There is something I don't understand at page 36 of these lecture notes (Author: Fiorenzo Bastianelli from the university of Bologna, title: Path integrals for fermions and supersymmetric quantum ...
2
votes
0answers
44 views

Mass insertions in Feynman diagrams

I'm trying to calculate some Feynman diagrams for $Z\rightarrow q\bar{q}$ at one-loop order in RPV SUSY with some $B$-violating vertices; these are triangle diagrams with 1-2 squark lines running in ...
0
votes
2answers
66 views

Dual of Kalb Ramond field [closed]

i've been studying string theory for 4 days, i have a Kalb Ramond $B_{(2)}$ of this kind (from a $5^2 _2$ solution [1]) and i want evaluate its dual but i don't obtain the right result: The variables ...
0
votes
0answers
24 views

What Standard Model extensions are getting constrained by today's new measurement of the electron's EDM?

As published today in Nature: Improved limit on the electric dipole moment of the electron (free to view) and summarized on Live Science. They improve on the previous measurements by an order of ...
1
vote
0answers
45 views

What should I learn to understand 6d (2,0) theory? [closed]

I'm a first-year graduate student, I heard that 6d (2,0) theories can provide various dualities between lower dimension field theories, and can give many beautiful results in mathematics. So I ...
2
votes
2answers
138 views

Why naturalness is an issue in particle physics? It is not in fluid dynamics

I have often heard that naturalness is a strong argument in favor of Supersymmetry. They say that there must be energy scales not too far away the EW-energy so that the quantum corrections of the ...
1
vote
0answers
28 views

Equations of motion for a Weyl spinor in the context of SUSY

I'm learning supergravity from the textbook of Antoine Van Proeyen (this is from page 114). Suppose I'm given a Lagrangian $$ \mathcal{L} = - \partial^{\mu} \bar{Z} \partial_{\mu} Z - \bar{\chi} \...
3
votes
1answer
68 views

Auxiliary Grassmann variables in supergeometry

I was reading on super geometry and how it is used to model fermions and supersymmetry in classical field theory. In texts like [1] or [2] the authors introduced auxiliary Grassmann odd variables to ...
1
vote
1answer
91 views

Can a rebranded super-symmetry be consistent with the null results at the LHC

To explain the null results on SUSY at the LHC, it continues to be assumed that the achievement of the energy threshold for the creation of the SUSY partners is beyond the capability of the ...
1
vote
1answer
66 views

Like the Higgs sector of the standard model, is there a SUSY sector which is also such a sector?

This question arose from an application of the virial theorem that showed how Bose-Einstein condensates of astrophysical dimension could arise from condensing clouds of normal phase bosons. If these ...
1
vote
0answers
56 views

Relation between Levi-Civita tensor and the trace of Lorentz transformations

here is this tricky identity to prove in an appendix of W.B. Supersymmetry and Supergravity that's driving me crazy. Some premises first: This book use the van der Waerden's convention for spinor ...
4
votes
0answers
67 views

Are there any SUSY black holes in D > 5?

Quoting from arXiv:0801.3471 Asymptotically flat BPS black hole solutions are known only for $d = 4,\,5$. and I've seen this claim very timidly suggested in a couple of other places, but I couldn'...
3
votes
0answers
80 views

What role does SUSY play in gauge/gravity duality?

This question arises in my project of finding the conformal field theory dual to the bosonic part of the Yang-Mills theory, i.e. non-supersymmetric large $N$ YM theory. Supersymmetry is a constant ...
1
vote
1answer
48 views

Temperature and Witten index

Assume that the spectrum of some supersymmetric theory is discrete, then the Witten index is expected to be independent of temperature given by $T = 1/\beta$. However, it is well-known (see this) that ...
4
votes
1answer
81 views

Can you quantize Grassmann-even superfields in the same fashion as Boson fields?

In a related Phys.SE question about supersymmetric Lagrangian $$ \mathcal{L} = - \frac{1}{2} (\partial S)^2 - \frac{1}{2} (\partial P)^2 - \frac{1}{2} \bar{\psi} \partial\!\!\!/ \psi, $$ the fields $S$...
4
votes
2answers
311 views

How are supersymmetry transformations even defined?

I am just starting to read about supersymmetry for the first time, and there is something bothering me. Supersymmetry transformations transform between bosonic fields and fermionic fields, but I don't ...
0
votes
0answers
55 views

Relation between groups and commutators

I am getting introduced into supersymmetry following chapter 11 of Ryder's Quantum Field Theory. I have a question about why $[\delta_1,\delta_2]=\Delta$ being this result independent of the field ...
2
votes
1answer
277 views

Why is there a maximum number of supersymmetries?

Where does the NO-GO theorem for a maximum number of supersymmetries come from? I read from here https://en.wikipedia.org/wiki/Supersymmetry that number is 32, and that fixes the number of spacetime ...
1
vote
1answer
44 views

Wess-Zumino model: simplified vs non-simplified?

According to Ryder Quantum Field Theory page 440 the "simplified Wess-Zumino model" has the lagrangian $$ \mathscr{L} = \frac{1}{2}(\partial_\mu A)^2 + \frac{1}{2}(\partial_\mu B)^2 + \frac{1}{4} \...
2
votes
1answer
82 views

Is it possible to break supersymmetry in such way that the SUSY partners of the known particles have a much lower mass as opposed to greater?

To continue, is it possible to break SUSY in a way that leaves some of the SUSY partners about equal in mass? These issues arose in connection with an unpublished ab initio calculation of the ...
1
vote
2answers
136 views

Why do we want supersymmetry transformations to form a group?

I am getting introduced into supersymmetry reading Ryder "Quantum Field Theory". I have taken an introductory course on QFT last semester so I am far from being an expert. Sorry if this is a silly ...
1
vote
1answer
90 views

On String Theory, Supersymmetry and prospects of a theory of everything

The fundamental postulate of string theory is that matter is composed of tiny vibrating loops of string, and each vibrational mode of the string corresponds to a different fundamental particle. Now, ...
1
vote
0answers
19 views

Does Natural SUSY predict any deviations in the Electron Dipole Moment?

There are projects underway that measure the Electron Dipole Moment (EDM). So far these experiments have ruled out some parameter space of some SUSY models. See here https://www.researchgate.net/...
7
votes
2answers
470 views

Supersymmetry: current 2018 status?

Sorry if this is a loose question, or if it is worth to be asked. What is the current status for "the principle of supersymmetry"? Was it observed in any experiment? Do we still believe it could ...
1
vote
0answers
60 views

Why does the SUSY vacuum energy vanish independently of the quantization scheme?

This question was inspired by the comments here. It is straightforward to show that the SUSY vacuum energy vanishes, $H|0 \rangle = 0$, using nothing but the SUSY algebra. For people who prefer a less ...
1
vote
0answers
24 views

$USp$ global symmetry in $d=3$, ${\cal N}=4$ supersymmetric QFT

Define a 3-dimensional QFT with $N=4$ supersymmetry (4 supercharges), and the field content is $g$ $N=4$ hyper-multiplets (that are in a representation $R$ of some group $G$). Each hyper-multiplet is ...
2
votes
0answers
28 views

Are twisted versions of supersymmetric field theories supersymmetric on any general four manifold?

Witten in his famous paper (Topological Quantum Field Theory) writes -- " I do not know whether twisted versions of other $\mathcal{N} \ge 2$ supersymmetric field theories will similarly be ...