PHY323:Lecture 11 SUSY and UED

Total Page:16

File Type:pdf, Size:1020Kb

Load more

PHY323:Lecture 11

SUSY and UED

••••

Higgs and Supersymmetry The Neutralino Extra Dimensions How WIMPs interact

Candidates for Dark Matter III

The New Particle Zoo

Here are a few of the candidates on a plot showing cross section vs. mass. An enormous range. We will focus on WIMPs

thanks to L. Roszkowski (Sheffield)

Freeze Out of Thermal DM Particles

WIMP Candidate 1
Supersymmetric Dark Matter

Each particle gets a “sparticle” counterpart. Bosons get fermions and vice versa.

e.g. Photon Photino
W

Z
Wino Zino etc

The Lightest Supersymmetric Particle (LSP) is predicted to be stable. This is called the NEUTRALINO.

Supersymmetry Theory

What we are aiming to do, e.g.: At higher energies, where symmetries are unbroken, you might expect a unified theory should have a single coupling constant

Supersymmetry Theory and the Higgs

To make things simpler, it would be nice if all the forces of nature were unified under the same theoretical framework. The energy at which this is likely called the Planck energy (1019 GeV).

This was started in the 1970s - the result is the electroweak theory. The theory is intricate and complicated, partly because the photon is massless, but the W & Z are heavy.

The electroweak theory posits that the very different carriers, and therefore properties, of these forces at energy scales present in nature today are actually the result of taking a much more symmteric theory at higher energies, above the ‘electroweak scale’ of 90GeV (the W and Z rest energy) and ‘spontaneously breaking’ it. The theoretical mechanism for spontaneous symmetry breaking requires yet another new particle, a spin zero particle called the HIGGS BOSON.

Massive Force Carriers

Extra Note

The carrier of the electromagnetic force is a massless photon.
The carriers of the weak force are heavy, having a rest energy of roughly 90GeV. They are weakly interacting massive particles.

Can these things be dark matter ? No, actually, because they are unstable. A

Are there other weakly interacting, massive particles which ARE stable, and therefore could be a candidate for dark matter ? Yes, but not within the standard model.

The “Higgs” is unstable, so it can’t be the dark matter itself

The Higgs endows the carriers of the weak force with their high mass, resulting in a feeble force with a short range. But now the standard model contains another particle, and when you look in to the properties of the Higgs, you hit problems. For example, the Higgs in electroweak theory has a coupling to two electrons and a four Higgs self-coupling.

Because of the Higgs mechanism, the standard model of particle physics is internally inconsistent. To remove the inconsistencies, extensions to the theory are needed.

SUPERSYMMETRY is a popular candidate extension.

Higgs Self
Energy

The quantum mechanical amplitude for a Higgs to travel from A to B, summed over all contributing processes is...

H

Notes
Fixing Higgs Self Energy Problem

In supersymmetry, each particle in the standard model has a supersymmetric partner with spin angular momentum differing by hbar/2. So for every fermion there is a supersymmetric partner boson and vice-versa.

The extra diagrams for the Higgs self energy where virtual superpartners are formed and destroyed cancel the divergent diagrams in the standard model sector, rendering the Higgs selfenergy finite.

In fact, it’s more complicated than this. The supersymmetric partners, none of which have been detected, mix together quantum mechanically, so that the actual supersymmetric objects we might detect in the LHC will be MIXTURES of the supersymmetric partners of the known particles.

A Lot to Buy Into ?

Supersymmetry is a lot to swallow. Twice the number of particles we have already found, and none of the superpartners detected yet ? To solve one puny Higgs self-energy problem?

Well, supersymmetry could do much more than this. (1) Some supersymmetric extensions, particularly supergravity, allow the possibility of quantizing the gravitational force, the biggest unsolved problem in quantum mechanics.

(2) Supersymmetry eases extrapolation to high energy unification

(3) The lightest supersymmetric particle might be stable. Lots of supersymmetric theories conserve something called R-parity, in which case a supersymmetric particle cannot decay into a set of non-supersymmetric particles.

Supersymmetric Partner Mixing

Lots of very clever people are working very hard on detecting the supersymmetric partners of ordinary particles, and if they do then they will sort out the mess of what supersymmetric states are actually observed in nature, and what their properties are.

Possibility of very exciting new physics if supersymmetry is detected at the LHC. Dan Tovey, Stathes Paganis, Davide Costanzo here at Sheffield.

SUSY and R Parity

SUSY introduces a new quantun number called R parity, in order to prevent proton decay and make distinguishable some states otherwise identical.

Introducing R parity and giving the value of 1 and -1 to the SM particles and their supersymmetric partners respectively, the two states become distinguishable.

The R parity is defined as

where B, L are the baryon and lepton number operators and S is the spin. R parity is a multiplicative symmetry, so sparticles are produced in pairs.

If R parity is broken, then there are no special selection rules to prevent the decay of those supersymmetric particles in the spectrum with masses of order of few GeV. In particular, the theory would possess no natural candidate for cold dark matter particles.

The Neutralino

The neutralino is a possibility for the lightest supersymmetric particle, and hence WIMPs. What is it? Well, it’s quite complicated.

The neutralino is a quantum mechanical superposition of the bino, wino and two higgsinos

SUSY DM Summary

Supersymmetry first formulated in the 1970s. Symmetry between fermions and bosons. Each SM particle has a ‘superpartner’ R-Parity introduced to prevent rapid proton decay - must be conserved. Leads to existence of a stable Lightest Supersymmetric Particle (LSP)

For SUSY to agree with
Standard Model:

Most important SUSY particle for
DM is the Neutralino.

10GeV < Mχ <104 GeV

Searches for charginos and squarks at LEP and Tevatron:

If this is the LSP, it is an ideal
WIMP candidate.
In most realistic SUSY models (i.e. no charged LSP), Neutralino IS LSP

Mχ > 50GeV

A natural candidate not invented to solve Dark Matter

Notes
WIMP Candidate 2

Kaluza-Klein Dark Matter

This important candidate comes from the theory of Universal

Extra Dimensions (UED) where all standard model particles

propagate into flat dimensions. It produces a WIMP called the

Lightest Kaluza-Klein particle (LKP).

Extra Dimensions

Extra dimensions is used to lower the fundamental Planck scale, MP ~ 1019 GeV, close to the electroweak scale by allowing gravity to propagate in (3 + 1) + n dimensions whilst confining the Standard Model particles to the 3 + 1 (Minkowski subspace)

In this case, the apparent Planck scale is related to the
MP ~ MF (RMF )n/2 fundamental scale MF via

size of the extra dimensions

As these extra dimensions modify the usual inverse-square law of gravity at distances < R, their size must be < 1mm in order not to conflict with the results from current short range gravitational experiments.

Any extra dimensions must therefore be compactified, and so R represents their compactification radius. A significant feature of extra dimensional theories is heavy ‘KaluzaKlein’ particles that can propagate in the extra dimensions.

KK Dark Matter Candidate

For 1 dimension plus 1 extra compact dimension, the compactification can be visualised as an infinite garden hose with a small but finite radius. At large distances only the length of the wire can be perceived, but sufficiently close to the wire the finite distance around the wire can also be resolved.

Consider 1 extra spatial dimensions curled up in a small circle

Particles moving in extra dimensions appear as a set of copies of normal particles.

LKP (lightest KK particle) is stable –dark matter!

KK Dark Matter Relic Density

Some predictions from UED for KK dark matter particles, showing that they could make up all the dark matter

Rather like R-parity in SUSY there is KK-parity (−1)KK in UED

Summary on DM particles

We like CDM and WIMPs and Neutralinos

(1) CDM favours structure formation (2) Such particles match well generic arguments about freeze-out in the Big Bang

(3) There are well motivated candidates predicted independently from particle physics

So WIMPs are the best generic candidate and of these we like Neutralinos from SUSY

Standard Model Particle Physics

Extra Note

This is a model that accounts for the vast majority of the known behaviour of the known particle types, either present in nature or discovered in accelerators. It supercedes older classical field theories like classical electromagnetism, which means that it explains all the phenomena explained by these theories and then also explains some outside the context of those theories.

It does NOT superscede classical gravitation !
The basic idea is that there is a set of fundamental spin-1/2 particles that interact with each other by the exchange of some fundamental spin-1 particles.

The word particle is used loosely here - these are quantum mechanical objects having both particle and wave-like properties.

EG: Quantum Electrodynamics - The quantum theory of electromagnetism

Extra Note

We know that electromagnetic radiation is emitted and absorbed by electrically charged particles being accelerated. What is the quantum foundation of this classical theory?

The quantum theory of electromagnetic interactions is called quantum electrodynamics. It was invented by Julian Schwinger, Richard Feynmann, and others in the 1950s.

Quantum electrodynamics is integral to the standard model of particle physics.

Classical vs. Quantum
Electrodynamics

Extra Note

fundamental coupling Scattering of charged particles by each other (Moller scattering)

scattering of light by charged particles (Compton scattering)

The Weak Interactions

Extra Note

Defining characteristics: (a) Much feebler than the electromagnetic interactions, at least when the energies of the interacting particles are much less than 90GeV. At 90GeV, they dominate over the electromagnetic interactions, and above 90GeV the strengths of the two interactions are compatible.

Hence the name...

(b) Short range - particles separated by more than the size of roughly an atomic nucleus will not be affected.

Because of these characteristics, weak interactions were not noticed until the latter half of the 20th century, and there was never any call for a classical theory of weak interactions.

So how do you make an interaction feeble and short range ?

Summary on SUSY

Particle theorists like supersymmetry because they could solve the higgs self energy problem, the problem of quantizing gravity and the problem of unifying the fundamental forces at high energies (in the early Universe) in one go!

Particle experimentalists like supersymmetry because

supersymmetric particles can be searched for in machines we can (just about) afford to build and run, and finding them may allow experiment to jump ahead of theory by providing sorely needed experimental data.

Particle Astrophysicists like supersymmetry because it yields a

class of dark matter candidates of about the right mass to close the universe with standard astrophysics phenomenology based on the standard model.

BUT making supersymmetric particles in accelerators does not prove they are dark matter !

Basic Neutralino/WIMP Properties

Main characteristics of the particles

••

Mass in the range Number density in the range De Broglie wavelength in the range per litre

Main characteristics of the collisions

•••

Short range Elastic - same particles come out as go in to collision.

-[7,8]

Rare - cross section upper limits are currently ~10 pb

Rare processes mean that we need as many ‘detectors’ as possible. Use solid matter, where each nucleus is a potential detector. Look for materials having CHARACTERISTIC SIGNATURES that are detectable by existing technology.

Notes

e.g. describe the relationship between the terms CDM, WIMP, Neutralino, LSP and LKP.

Neutralino Dark Matter Properties

REST ENERGY:

Lower limit because at this mas they would have been
Upper limit is that if the energy scale for supersymmetric detected in accelerators but partners is this high, they no

  • in fact have not been.
  • longer rid the standard model

of infinities. Thye may also over-close the Universe.

Recommended publications
  • CERN Courier–Digital Edition

    CERN Courier–Digital Edition

    CERNMarch/April 2021 cerncourier.com COURIERReporting on international high-energy physics WELCOME CERN Courier – digital edition Welcome to the digital edition of the March/April 2021 issue of CERN Courier. Hadron colliders have contributed to a golden era of discovery in high-energy physics, hosting experiments that have enabled physicists to unearth the cornerstones of the Standard Model. This success story began 50 years ago with CERN’s Intersecting Storage Rings (featured on the cover of this issue) and culminated in the Large Hadron Collider (p38) – which has spawned thousands of papers in its first 10 years of operations alone (p47). It also bodes well for a potential future circular collider at CERN operating at a centre-of-mass energy of at least 100 TeV, a feasibility study for which is now in full swing. Even hadron colliders have their limits, however. To explore possible new physics at the highest energy scales, physicists are mounting a series of experiments to search for very weakly interacting “slim” particles that arise from extensions in the Standard Model (p25). Also celebrating a golden anniversary this year is the Institute for Nuclear Research in Moscow (p33), while, elsewhere in this issue: quantum sensors HADRON COLLIDERS target gravitational waves (p10); X-rays go behind the scenes of supernova 50 years of discovery 1987A (p12); a high-performance computing collaboration forms to handle the big-physics data onslaught (p22); Steven Weinberg talks about his latest work (p51); and much more. To sign up to the new-issue alert, please visit: http://comms.iop.org/k/iop/cerncourier To subscribe to the magazine, please visit: https://cerncourier.com/p/about-cern-courier EDITOR: MATTHEW CHALMERS, CERN DIGITAL EDITION CREATED BY IOP PUBLISHING ATLAS spots rare Higgs decay Weinberg on effective field theory Hunting for WISPs CCMarApr21_Cover_v1.indd 1 12/02/2021 09:24 CERNCOURIER www.
  • Neutralino Dark Matter in Supersymmetric Models with Non--Universal Scalar Mass Terms

    Neutralino Dark Matter in Supersymmetric Models with Non--Universal Scalar Mass Terms

    CERN{TH 95{206 DFTT 47/95 JHU{TIPAC 95020 LNGS{95/51 GEF{Th{7/95 August 1995 Neutralino dark matter in sup ersymmetric mo dels with non{universal scalar mass terms. a b,c d e,c b,c V. Berezinsky , A. Bottino , J. Ellis ,N.Fornengo , G. Mignola f,g and S. Scop el a INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy b Dipartimento di FisicaTeorica, UniversitadiTorino, Via P. Giuria 1, 10125 Torino, Italy c INFN, Sezione di Torino, Via P. Giuria 1, 10125 Torino, Italy d Theoretical Physics Division, CERN, CH{1211 Geneva 23, Switzerland e Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA. f Dipartimento di Fisica, Universita di Genova, Via Dodecaneso 33, 16146 Genova, Italy g INFN, Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy Abstract Neutralino dark matter is studied in the context of a sup ergravityscheme where the scalar mass terms are not constrained by universality conditions at the grand uni cation scale. We analyse in detail the consequences of the relaxation of this universality assumption on the sup ersymmetric parameter space, on the neutralino relic abundance and on the event rate for the direct detection of relic neutralinos. E{mail: b [email protected], b [email protected], [email protected], [email protected], [email protected], scop [email protected] 1 I. INTRODUCTION The phenomenology of neutralino dark matter has b een studied extensively in the Mini- mal Sup ersymmetric extension of the Standard Mo del (MSSM) [1].
  • Non–Baryonic Dark Matter V

    Non–Baryonic Dark Matter V

    Non–Baryonic Dark Matter V. Berezinsky1 , A. Bottino2,3 and G. Mignola3,4 1INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ), Italy 2Universit`a di Torino, via P. Giuria 1, I-10125 Torino, Italy 3INFN - Sezione di Torino, via P. Giuria 1, I-10125 Torino, Italy 4Theoretical Physics Division, CERN, CH–1211 Geneva 23, Switzerland (presented by V. Berezinsky) The best particle candidates for non–baryonic cold dark matter are reviewed, namely, neutralino, axion, axino and Majoron. These particles are considered in the context of cosmological models with the restrictions given by the observed mass spectrum of large scale structures, data on clusters of galaxies, age of the Universe etc. 1. Introduction (Cosmological environ- The structure formation in Universe put strong ment) restrictions to the properties of DM in Universe. Universe with HDM plus baryonic DM has a Presence of dark matter (DM) in the Universe wrong prediction for the spectrum of fluctuations is reliably established. Rotation curves in many as compared with measurements of COBE, IRAS galaxies provide evidence for large halos filled by and CfA. CDM plus baryonic matter can ex- nonluminous matter. The galaxy velocity distri- plain the spectrum of fluctuations if total density bution in clusters also show the presence of DM in Ω0 ≈ 0.3. intercluster space. IRAS and POTENT demon- There is one more form of energy density in the strate the presence of DM on the largest scale in Universe, namely the vacuum energy described the Universe. by the cosmological constant Λ. The correspond- The matter density in the Universe ρ is usually 2 ing energy density is given by ΩΛ =Λ/(3H0 ).
  • Rethinking “Dark Matter” Within the Epistemologically Different World (EDW) Perspective Gabriel Vacariu and Mihai Vacariu

    Rethinking “Dark Matter” Within the Epistemologically Different World (EDW) Perspective Gabriel Vacariu and Mihai Vacariu

    Chapter Rethinking “Dark Matter” within the Epistemologically Different World (EDW) Perspective Gabriel Vacariu and Mihai Vacariu The really hard problems are great because we know they’ll require a crazy new idea. (Mike Turner in Panek 2011, p. 195) Abstract In the first part of the article, we show how the notion of the “universe”/“world” should be replaced with the newly postulated concept of “epistemologically different worlds” (EDWs). Consequently, we try to demonstrate that notions like “dark matter” and “dark energy” do not have a proper ontological basis: due to the correspondences between two EDWs, the macro-epistemological world (EW) (the EW of macro-entities like planets and tables) and the mega-EW or the macro– macro-EW (the EW of certain entities and processes that do not exist for the ED entities that belong to the macro-EW). Thus, we have to rethink the notions like “dark matter” and “dark energy” within the EDW perspective. We make an analogy with quantum mechanics: the “entanglement” is a process that belongs to the wave- EW, but not to the micro-EW (where those two microparticles are placed). The same principle works for explaining dark matter and dark energy: it is about entities and processes that belong to the “mega-EW,” but not to the macro-EW. The EDW perspective (2002, 2005, 2007, 2008) presupposes a new framework within which some general issues in physics should be addressed: (1) the dark matter, dark energy, and some other related issues from cosmology, (2) the main problems of quantum mechanics, (3) the relationship between Einstein’s general relativity and quantum mechanics, and so on.
  • R-Parity Violation and Light Neutralinos at Ship and the LHC

    R-Parity Violation and Light Neutralinos at Ship and the LHC

    BONN-TH-2015-12 R-Parity Violation and Light Neutralinos at SHiP and the LHC Jordy de Vries,1, ∗ Herbi K. Dreiner,2, y and Daniel Schmeier2, z 1Institute for Advanced Simulation, Institut f¨urKernphysik, J¨ulichCenter for Hadron Physics, Forschungszentrum J¨ulich, D-52425 J¨ulich, Germany 2Physikalisches Institut der Universit¨atBonn, Bethe Center for Theoretical Physics, Nußallee 12, 53115 Bonn, Germany We study the sensitivity of the proposed SHiP experiment to the LQD operator in R-Parity vi- olating supersymmetric theories. We focus on single neutralino production via rare meson decays and the observation of downstream neutralino decays into charged mesons inside the SHiP decay chamber. We provide a generic list of effective operators and decay width formulae for any λ0 cou- pling and show the resulting expected SHiP sensitivity for a widespread list of benchmark scenarios via numerical simulations. We compare this sensitivity to expected limits from testing the same decay topology at the LHC with ATLAS. I. INTRODUCTION method to search for a light neutralino, is via the pro- duction of mesons. The rate for the latter is so high, Supersymmetry [1{3] is the unique extension of the ex- that the subsequent rare decay of the meson to the light ternal symmetries of the Standard Model of elementary neutralino via (an) R-parity violating operator(s) can be particle physics (SM) with fermionic generators [4]. Su- searched for [26{28]. This is analogous to the production persymmetry is necessarily broken, in order to comply of neutrinos via π or K-mesons. with the bounds from experimental searches.
  • General Neutralino NLSP with Gravitino Dark Matter Vs. Big Bang Nucleosynthesis

    General Neutralino NLSP with Gravitino Dark Matter Vs. Big Bang Nucleosynthesis

    General Neutralino NLSP with Gravitino Dark Matter vs. Big Bang Nucleosynthesis II. Institut fur¨ Theoretische Physik, Universit¨at Hamburg Deutsches Elektronen-Synchrotron DESY, Theory Group Diplomarbeit zur Erlangung des akademischen Grades Diplom-Physiker (diploma thesis - with correction) Verfasser: Jasper Hasenkamp Matrikelnummer: 5662889 Studienrichtung: Physik Eingereicht am: 31.3.2009 Betreuer(in): Dr. Laura Covi, DESY Zweitgutachter: Prof. Dr. Gun¨ ter Sigl, Universit¨at Hamburg ii Abstract We study the scenario of gravitino dark matter with a general neutralino being the next- to-lightest supersymmetric particle (NLSP). Therefore, we compute analytically all 2- and 3-body decays of the neutralino NLSP to determine the lifetime and the electro- magnetic and hadronic branching ratio of the neutralino decaying into the gravitino and Standard Model particles. We constrain the gravitino and neutralino NLSP mass via big bang nucleosynthesis and see how those bounds are relaxed for a Higgsino or a wino NLSP in comparison to the bino neutralino case. At neutralino masses & 1 TeV, a wino NLSP is favoured, since it decays rapidly via a newly found 4-vertex. The Higgsino component becomes important, when resonant annihilation via heavy Higgses can occur. We provide the full analytic results for the decay widths and the complete set of Feyn- man rules necessary for these computations. This thesis closes any gap in the study of gravitino dark matter scenarios with neutralino NLSP coming from approximations in the calculation of the neutralino decay rates and its hadronic branching ratio. Zusammenfassung Diese Diplomarbeit befasst sich mit dem Gravitino als Dunkler Materie, wobei ein allge- meines Neutralino das n¨achstleichteste supersymmetrische Teilchen (NLSP) ist.
  • High Energy Neutrinos from Neutralino Annihilations in The

    High Energy Neutrinos from Neutralino Annihilations in The

    MADPH-07-1494 August 2007 High energy neutrinos from neutralino annihilations in the Sun Vernon Barger,1, ∗ Wai-Yee Keung,2, † Gabe Shaughnessy,1, ‡ and Adam Tregre1, § 1Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 USA 2Physics Department, University of Illinois at Chicago, Illinois 60607–7059 USA Abstract Neutralino annihilations in the Sun to weak boson and top quark pairs lead to high-energy neu- trinos that can be detected by the IceCube and KM3 experiments in the search for neutralino dark matter. We calculate the neutrino signals from real and virtual WW,ZZ,Zh, and tt¯ pro- duction and decays, accounting for the spin-dependences of the matrix elements, which can have important influences on the neutrino energy spectra. We take into account neutrino propagation including neutrino oscillations, matter-resonance, absorption, and ντ regeneration effects in the Sun and evaluate the neutrino flux at the Earth. We concentrate on the compelling Focus Point (FP) region of the supergravity model that reproduces the observed dark matter relic density. For the FP region, the lightest neutralino has a large bino-higgsino mixture that leads to a high neutrino flux and the spin-dependent neutralino capture rate in the Sun is enhanced by 103 over the spin-independent rate. For the standard estimate of neutralino captures, the muon signal rates in IceCube are identifiable over the atmospheric neutrino background for neutralino masses above MZ up to 400 GeV. arXiv:0708.1325v2 [hep-ph] 2 Nov 2007 ∗Electronic address: [email protected] †Electronic address: [email protected] ‡Electronic address: [email protected] §Electronic address: [email protected] 1 I.
  • Physics Case for Axions and Other Wisps

    Physics Case for Axions and Other Wisps

    Physics case for axions and other WISPs. Andreas Ringwald (DESY) Mini-workshop on searches for new particles with high power lasers, Forschungszentrum Jülich/Institut für Kernphysik, 24./25. Oktober 2012 Particles beyond the Standard Model?! > Standard Model (SM) of particle physics describes basic properties of known matter and forces Andreas Ringwald | Searches for new particles with high power lasers | Jülich, 24./25. Oktober 2012 | Page 2 Particles beyond the Standard Model?! > Standard Model (SM) of particle physics describes basic properties of known matter and forces > SM not a complete and fundamental theory: . No satisfactory explanation for values of its many parameters . No reconciliation of gravity with quantum mechanics Andreas Ringwald | Searches for new particles with high power lasers | Jülich, 24./25. Oktober 2012 | Page 3 Particles beyond the Standard Model?! > Standard Model (SM) of particle physics describes basic properties of known matter and forces > SM not a complete and fundamental theory: . No satisfactory explanation for values of its many parameters . No reconciliation of gravity with quantum mechanics . No explanation of the origin of dark energy and dark matter Andreas Ringwald | Searches for new particles with high power lasers | Jülich, 24./25. Oktober 2012 | Page 4 Particles beyond the Standard Model?! > Particle candidates of dark matter should feature . Feeble interactions with SM and with themselves . Non-relativistic momentum distribution at beginning of structure formation . Stability on cosmological time scales > These features can be realised by . Weakly interacting massive particles (WIMPs), e.g. neutralino LSP in case of SUSY extension . Very weakly interacting slim (in the sense of very light) particles (WISPs), e.g.
  • Neutralino Dark Matter Detection in Split Supersymmetry Scenarios

    Neutralino Dark Matter Detection in Split Supersymmetry Scenarios

    SISSA 95/2004/EP FSU–HEP–041122 Neutralino Dark Matter Detection in Split Supersymmetry Scenarios A. Masiero1, S. Profumo2,3 and P. Ullio3 1 Dipartimento di Fisica ‘G. Galilei’, Universit`adi Padova, and Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Via Marzolo 8, I-35131, Padova, Italy 2 Department of Physics, Florida State University 505 Keen Building, FL 32306-4350, U.S.A. 3 Scuola Internazionale Superiore di Studi Avanzati, Via Beirut 2-4, I-34014 Trieste, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34014 Trieste, Italy E-mail: [email protected], [email protected], [email protected] Abstract We study the phenomenology of neutralino dark matter within generic supersym- arXiv:hep-ph/0412058v2 19 Jan 2005 metric scenarios where the Gaugino and Higgsino masses are much lighter than the scalar soft breaking masses (Split Supersymmetry). We consider a low-energy model-independent approach and show that the guidelines in the definition of this general framework come from cosmology, which forces the lightest neutralino to have a mass smaller than 2.2 TeV. The testability of the framework is addressed by discussing all viable dark matter detection techniques. Current data on cos- mic rays antimatter, gamma-rays and on the abundance of primordial 6Li already set significant constraints on the parameter space. Complementarity among future direct detection experiments, indirect searches for antimatter and with neutrino telescopes, and tests of the theory at future accelerators, such as the LHC and a NLC, is highlighted. In particular, we study in detail the regimes of Wino-Higgsino mixing and Bino-Wino transition, which have been most often neglected in the past.
  • Supersymmetric Particle Searches

    Supersymmetric Particle Searches

    Citation: M. Tanabashi et al. (Particle Data Group), Phys. Rev. D 98, 030001 (2018) and 2019 update Supersymmetric Particle Searches m m The exclusion of particle masses within a mass range ( 1, 2) m −m will be denoted with the notation “none 1 2” in the VALUE column of the following Listings. The latest unpublished results are described in the “Supersymmetry: Experiment” review. See the related review(s): Supersymmetry, Part I (Theory) Supersymmetry, Part II (Experiment) CONTENTS: χ0 (Lightest Neutralino) mass limit e1 Accelerator limits for stable χ0 − e1 Bounds on χ0 from dark matter searches − e1 χ0-p elastic cross section − 1 eSpin-dependent interactions Spin-independent interactions Other bounds on χ0 from astrophysics and cosmology − e1 Unstable χ0 (Lightest Neutralino) mass limit − e1 χ0, χ0, χ0 (Neutralinos) mass limits e2 e3 e4 χ±, χ± (Charginos) mass limits e1 e2 Long-lived χ± (Chargino) mass limit ν (Sneutrino)e mass limit Chargede sleptons R-parity conserving e (Selectron) mass limit − R-partiy violating e e(Selectron) mass limit − R-parity conservinge µ (Smuon) mass limit − R-parity violating µ e(Smuon) mass limit − R-parity conservinge τ (Stau) mass limit − R-parity violating τ e(Stau) mass limit − Long-lived ℓ (Slepton)e mass limit − e q (Squark) mass limit e R-parity conserving q (Squark) mass limit − R-parity violating q e(Squark) mass limit − Long-lived q (Squark) masse limit b (Sbottom)e mass limit e R-parity conserving b (Sbottom) mass limit − e R-parity violating b (Sbottom) mass limit − e t (Stop) mass limit e R-parity conserving t (Stop) mass limit − R-parity violating t (Stop)e mass limit − Heavy g (Gluino) mass limite R-paritye conserving heavy g (Gluino) mass limit − R-parity violating heavy g e(Gluino) mass limit − Long-lived g (Gluino) mass limite Light G (Gravitino)e mass limits from collider experiments e Supersymmetry miscellaneous results HTTP://PDG.LBL.GOV Page 1 Created: 8/2/2019 16:43 Citation: M.
  • Sterile Neutrino

    Sterile Neutrino

    Right-handed sneutrino as cold dark matter of the universe Takehiko Asaka (EPFL Æ Niigata University) @ TAUP2007 (11/09/2007, Sendai) Refs: with Ishiwata and Moroi Phys.Rev.D73:061301,2006 Phys.Rev.D75:065001,2007 I. Introduction Dark Matter Content of the universe [WMAP ’06] Dark energy (74%) Baryon (4%) Dark matter (22%) What is dark matter??? z No candidate in SM ⇒ New Physics !!! z One attractive candidate LSP in supersymmetric theories LSP Dark Matter R-parity: ordinary SM particles: R-parity even (+1) additional superparticles: R-parity odd (-1) z Lightest superparticle (LSP) is stable z LSP is a good candidate of DM if it is neutral What is the LSP DM? z Lightest neutralino (= combination of neutral gauginos and higgsinos) Other candidates for LSP DM The lightest neutralino is NOT the unique candidate for the LSP DM z In supergravity, “gravitino” z In superstring, “modulino” z With Peccei-Quinn symmetry, “axino” z … Now, we know that the MSSM is incomplete accounting for neutrino oscillations Æ alternative candidate for the LSP DM In this talk, Introduce RH neutrinos to explain neutrino masses z In supersymmetric theories, RH neutrino + RH sneutrino fermion (Rp=+1) scalar (Rp=-1) If neutrino masses are purely Dirac-type, z Masses of RH sneutrinos come from SUSY breaking — z Lightest RH sneutrino can be LSP, z LSP RH sneutrino is a good candidate for CDM (i.e., can be realized) II. Right-handed sneutrino as dark matter Model MSSM + three right-handed (s)neutrinos assuming neutrino masses are purely Dirac-type z Yukawa couplings are very small z Small Yukawa couplings are natural in ‘tHooft’s sense — chiral symmetry of neutrinos is restored in the limit of vanishing Yukawa couplings Model (2) LSP = z only suppressed interaction: NLSP = MSSM-LSP z MSSM-LSP can be charged z rather long-lived: —typically Our claim: LSP as CDM How are produced in the early universe??? Production of RH sneutrino is not thermalized in the early universe!!! z Interaction rate of is very small: — Typically, How are produced in the early universe??? A.
  • Search for Wisps Gains Momentum

    Search for Wisps Gains Momentum

    CERN Courier September 2018 Dark matter Got radiation? Knirck/MPIS Search for See what you’ve been missing WISPs gains momentum Despite tremendous efforts, the search for the constituents of dark matter has so far been unsuccessful. Interest is therefore growing in new experiments that probe dark-matter candidates such as axions and other very weakly interacting sub-eV particles. PhotoPPhoPhotPhhhohotoottooc coccourtesyourteuurturrtertrtetesysyyo ooffEf E EUEUROfusion.URROfROfuROOfuOffufussiosionsiioniioonon..W WWeWebsite:ebsbsitbsitssiitite:e:w: wwww.euro-fusion.orgwwwww.ew.wweuro-urro-oo-fusfufusiusiusussiioon.oonon.nn.n.ono.o. orrgg Photo courtesy of EUROfusion. Website: www.euro-fusion.org Understanding the nature of dark matter is one of the most press- which is broken spontaneously in the vacuum. Such extensions ing problems in physics. This strangely nonreactive material is contain an additional scalar field with a potential shaped like a Imaging in radiation environments just got easier estimated, from astronomical observations, to make up 85% of all Mexican hat – similar to the Higgs potential in the SM (figure 1). matter in the universe. The known particles of the Standard Model This leads to spontaneous breaking of symmetry at a scale cor- (SM) of particle physics, on the other hand, account for a paltry 15%. responding to the radius of the trough of the hat: excitations in the With superior capabilities for operating in radiation environments, the MegaRAD cameras provide Physicists have proposed many dark-matter candidates. Two in direction along the trough correspond to a light Nambu–Goldstone excellent image quality well beyond dose limitations of conventional cameras, and are well suited particular stand out because they arise in extensions of the SM that (NG) boson, while the excitation in the radial direction perpen- solve other fundamental puzzles, and because there are a variety dicular to the trough corresponds to a heavy particle with a mass for radiation hardened imaging applications of experimental opportunities to search for them.