We investigate the possibility of a Nicolai map for minimal supergravity in four dimensions. Such a map would allow for the computation of quantum supergravity correlation functions in terms of flat-space correlators in an effective nonlocal bosonic theory with the help of a nonlinear field transformation, the inverse Nicolai map. Such a map is guaranteed for off-shell global supersymmetry, but local supersymmetry presents at least three obstacles for the construction. Their effects are analyzed in detail, in an attempt to set up a Nicolai map to leading order in the gravitational coupling. We find indications that the conformal factor of the metric obstructs the off-shell construction, suggesting that the unimodular variant of supergravity may do better. The on-shell supersymmetry approach, successful for super-Yang-Mills theory in its critical dimensions, also fails, because the graviton self-interaction cannot be written as a supervariation. Nevertheless, by brute force we obtain a four-parameter first-order Nicolai map fulfilling the free-action condition. For the acid test of determinant matching, however, one needs to push the general ansatz and the perturbative expansion to the second order and to the quantum level.

Germany

Federico Arrighi

Saurish Khandelwal

Olaf Lechtenfeld

Towards a Nicolai map for supergravity

New light particles have received considerable attention in recent years. Baryon-number-violating (BNV) nucleon decays involving such light particles are able to provide stringent constraints. They exhibit distinctive experimental signatures that merit thorough investigation. We systematically investigate BNV nucleon decay with a light scalar in an effective field theory framework. Within this framework, we set stringent bounds on BNV operators using available experimental data and predict the occurrence of several BNV three-body nucleon decays. We further study contributions to dinucleon to dilepton transitions in a nucleus mediated by the scalar, which complements single nucleon decay. Finally, we provide three ultraviolet-complete models that can generate different subsets of BNV operators in leading order. Our theoretical framework will facilitate experimental searches for those exotic nucleon decays.

China

Xiao-Dong Ma

Australia

Michael Schmidt

Weihang Zhang

Baryon-number-violating nucleon decays in SMEFT extended with a light scalar

We perform a systematic and comprehensive analysis of sub-leading colour corrections in perturbative QCD processes involving multiple soft gluon emissions. This necessitates going beyond the standard parton shower paradigm in order to incorporate interference effects and is accomplished using the CVolver program, which simulates parton showers at the amplitude level. We can compute cross-sections with full-colour precision and also broken down explicitly in terms of their $\textit{N}$ dependence. In this paper, we focus on the jet cross-section with a veto of additional jets in some fixed region of phase-space, since this is sensitive to wide-angle, soft gluon radiation. We consider $$ Z\to q\overline{q} $$ , $\textit{H}$ → $\textit{gg}$, $$ q\overline{q}\to q\overline{q} $$ , $\textit{qg}$ → $\textit{qg}$, $\textit{gg}$ → $\textit{gg}$ and colour-singlet → $$ q\overline{q}q\overline{q} $$ . We find that non-trivial sub-leading colour effects are generally important at the 5–30% level and much more than this for certain interference contributions. Remarkably, for this observable, we find that for all of the $\textit{t}$-channel gluon exchange processes that we consider, the strictly leading colour approximation, which includes the replacement $\textit{C}$ → $\textit{C}$ $\textit{/}$2, is an excellent approximation to the full colour result (up to an overall colour factor).

United Kingdom

Jeffrey Forshaw

Austria

Simon Plätzer

Fernando González

Exact colour evolution for jet observables

We consider the gauge algebra of closed string field theory with a focus on diffeomorphisms. This algebra contains off-shell information in two ways. The first way is geometric, through the choice of three-punctured sphere defining the three-string vertex. We establish that to leading order in derivatives the superstring algebra is universal: identical for any choice of vertex. For bosonic strings, however, some off-shell dependence remains for vertices that require symmetrization. Off-shell information also appears because field-dependent redefinition of the gauge parameters can alter the algebra. We analyze this dependence in the language of $\textit{L}$ algebras, looking at the role of trivial gauge transformations in the efforts to demonstrate that standard diffeomorphisms are part of the string gauge symmetry.

United States

Raji Mamade

Barton Zwiebach

Gauge algebra and diffeomorphisms in string field theory

We classify four dimensional $$ \mathcal{N}=2 $$ SCFTs whose Seiberg-Witten (SW) geometries can be written as hyperelliptic families. By using special Kähler condition of SW geometry, we reduce the problem to one parameter quasi-homogeneous hyperelliptic families $\textit{y}$ = $\textit{f}$($\textit{x, t}$). The classification is given by further demanding that the complex algebraic surface defined by $\textit{y}$ = $\textit{f}$($\textit{x, t}$) has an isolated singularity. We then write down the full SW geometry by looking at mini-versal deformations of the one parameter family, and the SW differential is also written down. The detailed physical data for these theories are found by matching the theory with other known construction. Our solutions recover the known rank one and rank two results, and give some infinite sequences valid at arbitrary ranks. We also studied $\textit{Z}$ quotient of above hyperelliptic families which give rise to $\textit{B}$ type and $\textit{D}$ type conformal gauge theory, and further generalizations.

Dan Xie

Zekai Yu

Hyperelliptic families and 4d $$ \mathcal{N}=2 $$ SCFT

We find a dual description of the supersymmetric SL(2, $\textit{ℂ}$)/SU(2) WZW model as a super-winding condensate CFT, which follows simply from the bosonic AdS duality found in [arXiv:2104.07233]. This duality can be seen as a dimensional uplift of the mirror symmetry between the $$ {H}_3^{+}/\textrm{U}(1) $$ supercoset and $$ \mathcal{N}=2 $$ super-Liouville theory.

Bhanu Narra

A supersymmetric AdS

We use equivariant localization and holography to study four-dimensional $$ \mathcal{N}=1 $$ superconformal field theories arising from M5-branes wrapped on a punctured Riemann surface. We explain how, given a Riemann surface with marked points, one can glue in a “puncture geometry” locally around each point. Using equivariant localization we show that the central charge consists of a bulk contribution plus localized puncture contributions. We recover and generalize the known results for locally $$ \mathcal{N}=2 $$ preserving punctures, and derive new results for genuinely locally $$ \mathcal{N}=1 $$ preserving punctures.

Christopher Couzens

Alice Lüscher

James Sparks

Localizing punctures in M-theory

We demonstrate some very special features of the Dirac-Born-Infeld-like (DBI) gravitational counter-term in AdS spacetime, in the context of holography with a sharp radial cut-off. We show that the three-sphere partition function is not only independent of a constant radial cut-off, but also remains unchanged under deformations of the cut-off surface. We also consider the renormalized holographic entanglement entropy for an equatorial Ryu-Takayanagi surface with a cut-off with an arbitrary shape and show that it can also be independent of the cut-off under a special condition. We also numerically study the behavior of the renormalized entropy with different counter-terms and relate the results to monotonicity properties under holographic renormalization group flow. The DBI counter-term is always seen to be associated with integrating out fewer degrees of freedom compared to other counter-terms.

India

Dileep Jatkar

Netherlands

Upamanyu Moitra

Finite Cut-Off Holography and the DBI Counter-Term

We investigate an extension of the Standard Model with a partially flavour non-universal abelian gauge symmetry that enables radiative mass generation for lighter fermions. With flavour-universal charges for the first two generations, gauge-induced loop corrections generate second-generation masses while keeping the first generation massless. Small first-generation masses can arise from subdominant scalar loops within this framework. A single anomaly-free U(1) is sufficient for a realistic model, and the partial universality relaxes the gauge boson mass bound from several thousand TeV to about 200 TeV compared with previous frameworks of this type. We also identify an alignment limit matching the lightest scalar to the observed Higgs and compute its couplings with the fermions, which largely agree with Standard Model values but show testable deviations.

Gurucharan Mohanta

Ketan Patel

Partially flavour non-universal U(1) and radiative fermion masses

Quiver Yangians are infinite-dimensional algebras capturing the BPS structure of a large class of supersymmetric models. Quiver theories related by Seiberg duality are expected to have isomorphic quiver Yangians, and this isomorphism has previously been shown for quivers corresponding to generalised conifold geometries. In this work, we present an explicit isomorphism for the two Seiberg dual phases of the $$ {\mathbbm{F}}_0 $$ quiver theory, which falls outside of the above class. Some aspects of our construction are similar to the known cases, while others appear to be specific to the $$ {\mathbbm{F}}_0 $$ quiver. In particular, the map involves square roots of operators bilinear in the fermionic fields of the mode being dualised.