In this paper we study non-factorizable $$ \mathcal{N} $$ = 1 superamplitudes for massive chiral superstates. We demonstrate how little group scaling and the supersymmetric Ward identities determine the form of non-factorizable massless superamplitudes, then extrapolate to massive superamplitudes by requiring they reduce to the massless form when we send all masses to zero. This technique does not depend on whether or not the superstates are self-conjugate (so that the fermionic components are either Dirac or Majorana) or whether the superamplitude is dressed with a form-factor.

United States

Antonio Delgado

Adam Martin

China

Runqing Wang

Non-factorizable superamplitudes for massive $$ \mathcal{N} $$ = 1 superstates

We identify $$ {m}_{12}^2 $$ as a spurion of non-invertible Peccei-Quinn symmetry in the type II 2HDM with gauged quark flavor. Thus a UV theory which introduces quark color-flavor monopoles can naturally realize alignment without decoupling and can furthermore revive the Weinberg-Wilczek axion. As an example we consider the SU(9) theory of color-flavor unification, which needs no new fermions. This is the first model-building use of non-invertible symmetry to find a Dirac natural explanation for a small $\textit{relevant}$ parameter.

Seth Koren

Non-invertible Peccei-Quinn symmetry, natural 2HDM alignment, and the visible axion

In this paper we develop a semi-standard Young tableau (SSYT) approach to construct a basis of non-factorizable superamplitudes in   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 1 massless supersymmetry. This amplitude basis can be directly translated to a basis for higher dimensional supersymmetric operators, yielding both the number of independent operators and their form. We deal with distinguishable (massless) chiral/vector superfields at first, then generalize the result to the indistinguishable case. Finally, we discuss the advantages and disadvantages of this method compared to the previously studied Hilbert series approach.

Basis for non-factorizable superamplitudes in   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 1 supersymmetry

In this paper we develop a Young diagram approach to constructing higher dimensional operators formed from massless superfields and their superderivatives in   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 1 supersymmetry. These operators are in one-to-one correspondence with non-factorizable terms in on-shell superamplitudes, which can be studied with massless spinor helicity techniques. By relating all spin-helicity variables to certain representations under a hidden U(N) symmetry behind the theory, we show each non-factorizable superamplitude can be identified with a specific Young tableau. The desired tableau is picked out of a more general set of U(N) tensor products by enforcing the supersymmetric Ward identities. We then relate these Young tableaux to higher dimensional superfield operators and list the rules to read operators directly from Young tableau. Using this method, we present several illustrative examples.

Hidden U(N) symmetry behind   <math> <mi>N</mi> </math>  $$ \mathcal{N} $$  = 1 superamplitudes

Following a recent publication, in this paper we count the number of independent operators at arbitrary mass dimension in N = 1 supersymmetric gauge theories and derive their field and derivative content. This work uses Hilbert series machinery and extends a technique from our previous work on handling integration by parts redundancies to vector superfields. The method proposed here can be applied to both abelian and non-abelian gauge theories and for any set of (chiral/antichiral) matter fields. We work through detailed steps for the abelian case with single flavor chiral superfield at mass dimension eight, and provide other examples in the appendices.

Counting operators in N = 1 supersymmetric gauge theories

In this paper we introduce a Hilbert series approach to build the operator basis for a N = 1 supersymmetry theory with chiral superfields. We give explicitly the form of the corrections that remove redundancies due to the equations of motion and integration by parts. In addition, we derive the maps between the correction spaces. This technique allows us to calculate the number of independent operators involving chiral and antichiral superfields to arbitrarily high mass dimension. Using this method, we give several illustrative examples.

Constructing operator basis in supersymmetry: a Hilbert series approach

Current searches for squarks are inefficient in cases when the squark does not directly decay to the lightest supersymmetric particle (LSP), because those decays are Yukawa suppressed. This occurs when producing the first two generations of squarks and when, at the same time, there are several electroweakinos lighter than those squarks. In this paper, we analyze the signal of the pair production of squarks that subsequently decay to an intermediate neutralino (<math><msubsup><mover><mi>χ</mi><mo>˜</mo></mover><mn>3</mn><mn>0</mn></msubsup></math>) plus jets. The neutralino will then decay to the LSP (mainly Higgsino) and a Higgs. We have simulated the events and designed a discovery strategy based on a signal of two jets, four <math><mi>b</mi></math> quarks, and missing transverse energy. We obtain very promising values for the Large Hadron Collider sensitivity at 14 TeV and <math><mn>300</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>.

Argentina

Spain

Ernesto Arganda

Roberto A. Morales

Mariano Quirós

Hunting squarks in Higgsino LSP scenarios at the LHC

The possibility in supersymmetric scenarios that the dark matter candidate is a Higgsino-like neutralino means that its production can be associated with Higgs bosons. Taking advantage of this fact, we propose a LHC search strategy for gluinos with  $$\tau $$  <math> <mi>τ</mi> </math>   leptons in the final state, coming from the decay of a Higgs boson. We consider the strong production of a pair of gluinos, one of which decays into the Higgsino plus jets while the other decays into the bino plus jets. In turn, this bino decays into the Higgsino plus a Higgs boson which finally decays into a  $$\tau $$  <math> <mi>τ</mi> </math>  -lepton pair. Therefore, the experimental signature under study consists of 4 jets, 2  $$\tau $$  <math> <mi>τ</mi> </math>   leptons, and a large amount of missing transverse energy. This work represents a proof of principle of a search that is sensitive to a spectrum such that the gluino does not directly decay to the dark matter candidate but to an intermediate electroweakino that then produces Higgs bosons in its subsequent decay. Our cut-based search strategy allows us to reach, for a LHC center-of-mass energy of 14 TeV and a total integrated luminosity of 1 ab $$^{-1}$$  <math> <msup> <mrow></mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </math>  , significances of up to 2 standard deviations, considering systematic uncertainties in the SM background of 30%. The projections for 3 ab $$^{-1}$$  <math> <msup> <mrow></mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </math>   are encouraging, with significances at the evidence level, which in more optimistic experimental scenarios could exceed 4 standard deviations.

Roberto Morales

Search strategy for gluinos at the LHC with a Higgs boson decaying into tau leptons

In the LHC searches for gluinos it is usually assumed that they decay predominantly into the lightest neutralino plus jets. In this work we perform a proof-of-concept collider analysis of a novel supersymmetric signal in which gluinos decay mostly into jets and the bino-like neutralino (<math><msubsup><mover><mi>χ</mi><mo>˜</mo></mover><mn>3</mn><mn>0</mn></msubsup></math>), which in turn decays into the lightest Higgsino-like neutralino (<math><msubsup><mover><mi>χ</mi><mo>˜</mo></mover><mn>1</mn><mn>0</mn></msubsup></math>), considered the dark matter candidate, together with the SM-like Higgs boson (<math><mi>h</mi></math>). This new physics signal then consists of an LHC final state made up by four light jets, four <math><mi>b</mi></math>-jets, and a large amount of missing transverse energy. We identify <math><mi>t</mi><mover><mi>t</mi><mo>¯</mo></mover></math>, <math><mi>V</mi><mo>+</mo><mrow><mtext>jets</mtext></mrow></math> (<math><mi>V</mi><mo>=</mo><mi>W</mi></math>, <math><mi>Z</mi></math>), and <math><mi>t</mi><mover><mi>t</mi><mo>¯</mo></mover><mo>+</mo><mi>X</mi></math> (<math><mi>X</mi><mo>=</mo><mi>W</mi></math>, <math><mi>Z</mi></math>, <math><msup><mi>γ</mi><mo>*</mo></msup></math>, <math><mi>h</mi></math>) productions as the most problematic backgrounds, and develop a search strategy for the high luminosity phase of the LHC, reaching signal significances at the evidence level for a luminosity of <math><mrow><mn>1000</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. The prospects for a luminosity of <math><mrow><mn>3000</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> are even more promising, with discovery-level significances.

Novel Higgsino dark matter signal interpretation at the LHC

A cosmologically stable neutral component from a nearly pure <math><mi>S</mi><mi>U</mi><mo>(</mo><mn>2</mn><mo>)</mo></math> doublet, with a mass <math><mo>∼</mo><mn>1.1</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, is one appealing candidate for dark matter (DM) consistent with all direct dark matter searches. We explore this possibility in the context of the minimal supersymmetric extension of the Standard Model, with the Higgsino playing the role of DM, in theories where supersymmetry breaking is transmitted by gravitational interactions at the unification scale <math><mi>M</mi><mo>≃</mo><mn>2</mn><mo>×</mo><msup><mn>10</mn><mn>16</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. We focus on the search for “light” supersymmetric spectra, which could be within reach of present and/or future colliders, in models with universal and nonuniversal Higgs and gaugino Majorana masses. The lightest supersymmetric particles of the spectrum are, by construction, two neutralinos and one chargino, almost degenerate, with a mass <math><mo>∼</mo><mn>1.1</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, and a mass splitting of a few GeV. Depending on the particular scenario the gluino can be at its experimental lower mass bound <math><mo>∼</mo><mn>2.2</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>; in the squark sector, the lightest top squark can be as light as <math><mo>∼</mo><mn>1.6</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, and the lightest slepton, the right-handed stau, can have a mass as light as 1.2 TeV. The lightest neutralino can be found in the next generation of direct dark matter experimental searches. In the most favorable situation, the gluino, with some specific decay channels, could be found during the next run of the LHC, and the lightest top squark during the high-luminosity LHC run.