A5087003738- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Computational Physics and Python Applications
- Superconducting Materials and Applications
University of Milano-Bicocca
2021-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca
2021-2024
Deutsches Elektronen-Synchrotron DESY
2019
We present a new calculation for the production of isolated photon pairs at LHC with NNLL$'_{\mathcal{T}_0}$+NNLO accuracy. This is first implementation within GENEVA Monte Carlo framework process nontrivial Born-level definition which suffers from QED singularities. Throughout computation we use smooth-cone isolation algorithm to remove such divergences. The higher-order resummation 0-jettiness resolution variable $\mathcal{T}_0$ based on factorisation formula derived Soft-Collinear...
We extend the geneva Monte Carlo framework using transverse momentum of a color-singlet system as resolution variable. This allows us to use next-to-next-to-next-to-leading-logarithm (${\mathrm{N}}^{3}\mathrm{LL}$) resummation via radish formalism obtain precise predictions for any production process at fully exclusive level. Thanks implementation two different variables within framework, we are able assess impact such choice on differential observables first time. As application, present...
We present the resummation of one-jettiness for color-singlet plus jet production process <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>p</a:mi><a:mi>p</a:mi><a:mo stretchy="false">→</a:mo><a:mo stretchy="false">(</a:mo><a:msup><a:mi>γ</a:mi><a:mo>*</a:mo></a:msup><a:mo>/</a:mo><a:mi>Z</a:mi><a:mo stretchy="false">→</a:mo><a:msup><a:mo>ℓ</a:mo><a:mo>+</a:mo></a:msup><a:msup><a:mo>ℓ</a:mo><a:mo>−</a:mo></a:msup><a:mo...
We present a novel next-to-next-to-leading order (NNLO) QCD calculation matched to parton shower for the production of pair $Z$ bosons decaying four massless leptons, $p p \to \ell^+ \ell^- \ell'^+ \ell'^- + X$, at LHC. Spin correlations, interferences and off-shell effects are included throughout. Our result is based on resummed beam-thrust spectrum, which we evaluate next-to-next-to-leading-logarithmic (NNLL$'_{\mathcal{T}_0}$) accuracy first time this process, makes use GENEVA Monte Carlo...
We present an event generator for the process $pp\to \ell\nu_\ell\gamma$ at next-to-next-to-leading order (NNLO) in QCD and matched to PYTHIA8 parton shower. The calculation makes use of GENEVA framework, which combines a resummed obtained via Soft-Collinear Effective Theory (SCET) with fixed-order result. validate NNLO accuracy our results by comparing predictions inclusive quantities independent calculation, then 0-jettiness spectrum logarithmic (NNLL$'$) accuracy. Finally, we compare...
Abstract Parton distribution functions (PDFs) are an essential ingredient for theoretical predictions at colliders. Since their exact form is unknown, handling and delivery practical applications relies on approximate numerical methods. We discuss the implementation of PDFs based a global interpolation in terms Chebyshev polynomials. demonstrate that this allows significantly higher accuracy lower computational cost compared with local methods such as splines. Whilst inaccuracy currently...
We show that soft gluons exchanged between the two colliding protons in multiparton scattering processes can be decoupled, such their effects are described by vacuum expectation values of Wilson lines. Our argument relies on nonabelian Ward identities and generalises proof factorisation for single Drell-Yan production given Collins, Soper Sterman.
We describe a number of improvements to the GENEVA method for matching NNLO calculations parton shower programs. In particular, we detail changes resummed calculation used in procedure, including disentangling cross section dependence on factorisation and beam scales, an improved treatment timelike logarithms. also discuss modifications implementation splitting functions which serve make differential higher multiplicity phase space. These improve stability numerical cancellation nonsingular...
In this work, we study the production of Higgs boson pairs at next-to-next-to-leading order in QCD matched to parton showers, using \textsc{Geneva} framework and working heavy-top-limit approximation. This includes resummation large logarithms zero-jettiness $\mathcal{T}_0$ up next-to-next-to-next-to-leading-log accuracy. process features an extremely momentum transfer, which makes its particularly relevant for matching schemes such as that employed \textsc{Geneva}, where a variable...
A bstract We present the NNLL′ resummed 2-jettiness distribution for decays of Standard Model Higgs boson to a b $$ \overline{b} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>b</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> -quark pair and gluons. The calculation exploits factorisation formula derived using Soft-Collinear Effective Theory, in which large logarithms are by renormalisation group evolution hard, soft jet contributions differential decay...
Double parton distributions are the nonperturbative ingredients needed for computing double scattering processes in hadron-hadron collisions. They describe a variety of correlations between two partons hadron and depend on large number variables, including independent renormalization scales. This makes it challenging to compute their scale evolution with satisfactory numerical accuracy while keeping computational costs at manageable level. We show that this problem can be solved using...
A bstract Double parton distributions can be computed from the perturbative splitting of one into two if distance between observed partons is small. We develop schemes to take account quark mass effects in this computation, and we study these numerically at leading order strong coupling. Furthermore, investigate detail structure next-to-leading corrections kernels that include effects.
We present an efficient numerical solution of the DGLAP equations for single and double parton distribution functions (PDFs DPDs), based on Chebyshev interpolation these functions. For PDF evolution, our method allows a higher accuracy using considerably smaller number grid points compared to other methods. The DPD evolution is realized affordable points, two independent renormalization scales partons. Both methods include NNLO kernels flavor matching.
We present the resummation of one-jettiness for colour-singlet plus jet production process $p p \to ( \gamma^*/Z \ell^+ \ell^-) + {\text{jet}}$ at hadron colliders up to fourth logarithmic order (N$^3$LL). This is first this processes involving three coloured partons Born level. match our formula corresponding fixed-order predictions, extending validity results regions phase space where further hard emissions are present. result paves way construction next-to-next-to-leading simulations...
We describe a number of improvements to the GENEVA method for matching NNLO calculations parton shower programs. In particular, we detail changes resummed calculation used in procedure, including disentangling cross section dependence on factorisation and beam scales, an improved treatment timelike logarithms. also discuss modifications implementation splitting functions which serve make differential higher multiplicity phase space. These improve stability numerical cancellation nonsingular...
Double parton distributions are the nonperturbative ingredients needed for computing double scattering processes in hadron-hadron collisions. They describe a variety of correlations between two partons hadron and depend on large number variables, including independent renormalization scales. This makes it challenging to compute their scale evolution with satisfactory numerical accuracy while keeping computational costs at manageable level. We show that this problem can be solved using...
We present an efficient numerical solution of the DGLAP equations for single and double parton distribution functions (PDFs DPDs), based on Chebyshev interpolation these functions. For PDF evolution, our method allows a higher accuracy using considerably smaller number grid points compared to other methods. The DPD evolution is realized affordable points, two independent renormalization scales partons. Both methods include NNLO kernels flavor matching.
Double parton distributions can be computed from the perturbative splitting of one into two if distance between observed partons is small. We develop schemes to take account quark mass effects in this computation, and we study these numerically at leading order strong coupling. Furthermore, investigate detail structure next-to-leading corrections kernels that include effects.
In this work, we study the production of Higgs boson pairs at next-to-next-to-leading order in QCD matched to parton showers, using \textsc{Geneva} framework and working heavy-top-limit approximation. This includes resummation large logarithms zero-jettiness $\mathcal{T}_0$ up next-to-next-to-next-to-leading-log accuracy. process features an extremely momentum transfer, which makes its particularly relevant for matching schemes such as that employed \textsc{Geneva}, where a variable...