We estimate the magnitude of the leading $\textit{non-perturbative}$ QCD corrections to the decays of the Higgs boson to the $\textit{γZ}$ and $\textit{γγ}$ final states. These corrections originate from the light-quark contributions to such decays. We show that the non-perturbative effects are suppressed by the small Yukawa couplings of light quarks, but that there is no further quark-mass suppression. This is at variance with what is found in the standard perturbative calculations of the light-quark contributions. We demonstrate that the non-perturbative corrections modify the $\textit{H}$ → $\textit{γZ}$ and $\textit{H}$ → $\textit{γγ}$ decay rates by $$ \mathcal{O}\left({10}^{-5}\right) $$ , well below the expected precision with which such decays can be studied both at the high-luminosity LHC and at future colliders.

Germany

Alexander Khodjamirian

Kirill Melnikov

United States

Arkady Vainshtein

Non-perturbative effects in Higgs boson decays to electroweak vector bosons and photons

We present a semi-analytic calculation of the integrated double-emission eikonal function of two massive emitters whose momenta are at an arbitrary angle to each other. This result is needed for extending the nested soft-collinear subtraction scheme [$\textit{Eur. Phys. J. C}$ (2017) 248] to processes with massive partons.

Ming-Ming Long

Andrey Pikelner

Integral of the double-emission eikonal function for two massive emitters at an arbitrary angle

We compute the next-to-leading-power corrections in the $\textit{N}$-jettiness variable to the production of a prompt photon and a jet at next-to-leading order in perturbative QCD in the $$ q\overline{q} $$ annihilation channel. We employ the $\textit{k}$ jet algorithm and assume that the $\textit{N}$-jettiness value divided by the jet transverse momentum is the smallest parameter in the problem; in particular it should be small compared to the jet radius $\textit{R}$.

Prem Agarwal

Ivan Pedron

Power corrections to the production of a prompt photon in association with a jet in the $\textit{N}$-jettiness slicing scheme at NLO QCD

We present integrated subtraction terms and finite remainders for $\textit{arbitrary}$ processes with massless partons at hadron and lepton colliders in the context of the nested soft-collinear subtraction scheme. These results provide the very last ingredients needed to make this scheme a fully local, analytic and process-independent framework for treating infrared singularities at next-to-next-to-leading order in perturbative QCD. The explicit infrared finiteness of all required contributions, as well as their process-independence, puts these results on par with subtraction schemes developed for next-to-leading order computations and opens up a clear path towards the automation of next-to-next-to-leading order computations in QCD.

Federica Devoto

Italy

Raoul Röntsch

Chiara Signorile-Signorile

Davide Tagliabue

Matteo Tresoldi

Integrated subtraction terms and finite remainders for arbitrary processes with massless partons at colliders in the nested soft-collinear subtraction scheme

In this work, we explore the vacuum and plasma magnetosphere of a slowly rotating, magnetized neutron star in a conformally coupled scalar field, so-called Bocharova–Bronnikov-Melnikov–Bekenstein (BBMB) geometry. Starting from the vacuum solutions to Maxwell’s equations in a curved spacetime, we derive modified magnetic and electric field structures in the BBMB geometry. We then investigate the behavior of the Goldreich–Julian (GJ) charge density, accelerating electric fields parallel to magnetic field lines, pair production thresholds, and the rate of energy loss through dipolar radiation in the magnetized star. The coupled scalar field significantly enhances magnetic field strength, charge separation, and parallel acceleration, as well as particle acceleration. We also study the deathline conditions that are responsible for secondary pair formation in the BBMB geometry. All results are compared with the general relativistic (GR) limit. As a result, deathline in the $$P-\dot{P}$$ diagram is located above in the spacetime compared with GR frame, implying extended pulsar activity compared to GR. Radiative luminosities from the magnetodipolar radiation process are also increased compared to GR predictions. These findings suggest that BBMB gravity could play a crucial role in shaping the high-energy phenomena of neutron stars and offer new avenues for testing gravity in strong-field regimes.

Uzbekistan

Sherzod Sayfiyev

Saudi Arabia

Ashfaque Bokhari

China

Bobomurat Ahmedov

Javlon Rayimbaev

Vacuum and plasma magnetosphere around rotating magnetized neutron stars in Bocharova–Bronnikov–Melnikov–Bekenstein geometry

<p>Recently, it was observed that an aggressive cut on the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math> jets’ transverse momenta applied to Higgs boson production in weak-boson fusion followed by the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> leads to very large QCD corrections to the fiducial cross section. In this paper, we show that these corrections are caused by soft and collinear QCD radiation and, therefore, can be efficiently treated by a parton shower. We combine the parton-shower description of the decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> with next-to-next-to-leading order QCD corrections to Higgs production in weak-boson fusion and its subsequent decay and demonstrate that the quality of the theoretical prediction is markedly improved even if <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math> jets with rather high transverse momenta are selected. The remaining uncertainty of the theoretical prediction, mainly driven by imprecise modeling of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>H</mi><mo stretchy="false">→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="false">¯</mo></mover></math> decay, is estimated to be of the order of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>5</mn><mi>–</mi><mn>7</mn><mo>%</mo><mo stretchy="false">)</mo></mrow></math>.</p>

Arnd Behring

Ivan Novikov

Giulia Zanderighi

Parton-shower and fixed-order QCD effects in Higgs boson production in weak-boson fusion and its decays to bottom quarks

<p>We study the impact of the pointlike <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi><msup><mover accent="true"><mi>q</mi><mo stretchy="false">¯</mo></mover><mo>′</mo></msup><mi>W</mi><mi>H</mi></math> interactions originating from a subset of dimension-six operators of the Standard Model effective field theory (SMEFT) on the Higgs boson associated production <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mi>p</mi><mo stretchy="false">→</mo><msup><mi>W</mi><mo>+</mo></msup><mi>H</mi></math> at the LHC. For consistency, we also take into account the corresponding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>q</mi><msup><mover accent="true"><mi>q</mi><mo stretchy="false">¯</mo></mover><mo>′</mo></msup><mi>W</mi></math> vertices implied by these operators. We compute the next-to-next-to-leading order quantum chromodynamics (QCD) corrections to this process and compare these corrections in the Standard Model and SMEFT production mechanisms.</p>

Marco Bonetti

Robert V. Harlander

Dmitrii Korneev

Davide Maria Tagliabue

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi><mi>H</mi></math> production at the LHC within SMEFT at next-to-next-to-leading order QCD

We describe the calculation of integrated subtraction terms in the nested soft-collinear subtraction scheme for hadron collider processes with quarks and gluons, thereby extending the results presented in ref. [1]. Although this extension eventually proves to be straightforward, it requires a more careful treatment of certain collinear limits to achieve a compact and physically-transparent final result. We also show that the cancellation of infrared divergences can be organized in such a way that, once soft contributions are removed, it occurs independently for each of the external partons. We consider these results to be important stepping stones on the way to deriving finite remainders of the integrated subtraction terms for fully-general hadron collider processes in the context of the nested soft-collinear subtraction scheme.

Towards a general subtraction formula for NNLO QCD corrections to processes at hadron colliders: final states with quarks and gluons

We compute next-to-leading power corrections in the zero-jettiness variable for the production of colorless final states at hadron colliders at next-to-leading order in QCD. To assess if the process-independence of leading power contributions can be extended, we attempt to construct generic expansions of phase spaces and matrix elements squared through next-to-leading power in the zero-jettiness. We highlight challenges associated with the collinear limit, where universality no longer holds at the subleading power, making the result process-dependent. We show that quantities that need to be calculated in the collinear limit can be obtained using Berends-Giele currents, enabling computation of power corrections to high-multiplicity final states. As a concrete example, we apply our method to compute power corrections in the zero-jettiness for lepton pair as well as multi-photon production in $$ q\overline{q} $$ collisions.

Philip Pfohl

Power corrections to the production of a color-singlet final state in hadron collisions in the $\textit{N}$-jettiness slicing scheme at NLO QCD

We present an analytic calculation of the integrated double-emission eikonal function of a massive and a massless emitter whose momenta are at an arbitrary angle to each other. This quantity provides one of the required ingredients for extending the nested soft-collinear subtraction scheme to processes with massive final-state particles. To calculate it, we use the standard methodology involving reverse unitarity and its extension to cases with Heaviside functions, integration-by-parts technology and reduction to master integrals, and differential equations. In addition, we also describe a semi-numerical method based on the subtraction of infra-red and collinear singularities from the eikonal function, allowing us to extract divergences of the integrated eikonal function analytically, and to derive a simple integral representation for the finite remainder.

Dennis Horstmann

Integral of the double-emission eikonal function for a massive and a massless emitter at an arbitrary angle