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P. Azzurri

Publications and source records attributed to P. Azzurri.

14 recordsLinked to original sources

ECFA Higgs, electroweak, and top Factory Study

The ECFA Higgs, electroweak, and top Factory Study ran between 2021 and 2025 as a broad effort across the experimental and theoretical particle physics communities, bringing together participants from many different proposed future collider projects. Activities across three main working groups advanced the joint development of tools and analysis techniques, fostered new considerations of detector design and optimisation, and led to a new set of studies resulting in improved projected sensitivities across a wide physics programme. This report demonstrates the significant expansion in the state-of-the-art understanding of the physics potential of future e+e- Higgs, electroweak, and top factories, and has been submitted as input to the 2025 European Strategy for Particle Physics Update.

hep-ex

Les Houches 2019: Physics at TeV Colliders: Standard Model Working Group Report

This Report summarizes the proceedings of the 2019 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments for high precision Standard Model calculations, (II) the sensitivity of parton distribution functions to the experimental inputs, (III) new developments in jet substructure techniques and a detailed examination of gluon fragmentation at the LHC, (IV) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, and (V) Monte Carlo event generator studies relating to PDF evolution and comparisons of important processes at the LHC.

hep-ph

Data-taking strategy for the precise measurement of the $W$ boson mass with a threshold scan at circular electron positron colliders

Circular electron positron colliders, such as the CEPC and FCC-ee, have been proposed to measure Higgs boson properties precisely, test the Standard Model, search for physics beyond the Standard Model, and so on. One of the important goals of these colliders is to measure the $W$ boson mass with great precision by taking data around the $W$-pair production threshold. In this paper, the data-taking scheme is investigated to maximize the achievable precisions of the $W$ boson mass and width with a threshold scan, when various systematic uncertainties are taken into account. The study shows that an optimal and realistic data-taking scheme is to collect data at three center-of-mass energies and that precisions of 1.0 MeV and 3.4 MeV can be achieved for the mass and width of the $W$ boson, respectively, with a total integrated luminosity of $\mathcal{L}=3.2$~\mbox{ab}$^{-1}$ and several assumptions of the systematic uncertainty sources.

hep-ex

Physics Behind Precision

This document provides a writeup of contributions to the FCC-ee mini-workshop on "Physics behind precision" held at CERN, on 2-3 February 2016.

hep-ph

First observation and measurement of the resonant structure of the lambda_b->lambda_c pi-pi+pi- decay mode

We present the first observation of the lambda_b->lambda_c pi-pi+pi- decay using data from an integrated luminosity of approximately 2.4 fb-1 of ppbar collisions at ECM=1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. We also present the first observation of the resonant decays lambda_b->sigma_c(2455)0 pi+pi- ->lambda_c pi-pi+pi-, lambda_b->sigma_c(2455)++ pi-pi- ->lambda_c pi-pi+pi-, lambda_b->lambda_c(2595)+ pi- ->lambda_c pi-pi+pi- and lambda_b->lambda_c(2625)+ pi- ->lambda_c pi-pi+pi-, and measure their relative branching ratios.

hep-ex

Studies of Fragmentation and Colour Reconnection at LEP

Hadronic events at the Z pole have been investigated in search for Colour Reconnection effects and QCD coherence. Colour Reconnection effects are searched for in three-jet events and the data results are compared to the predictions of different Monte Carlo models. QCD colour coherence effects are tested through the multiplicity distributions of hadrons with restricted momenta, and the LEP1 e+e- data is compared to HERA e+p data under the equivalence assumption of the e+e- hemisphere with the current region of the Breit frame of reference.

hep-ex

WW Production, Polarisation and Spin Correlations at LEP

Results on W-pair productions at LEP2 are reviewed and their consistency with standard electroweak expectations is summarised. Special interest is given to measurements of W polarisation, and to new studies of spin and decay-plane correlations among the W pairs.

hep-ex

The CMS Silicon Strip Tracker

With over 200 square meters of sensitive Silicon and almost 10 million readout channels, the Silicon Strip Tracker of the CMS experiment at the LHC will be the largest Silicon strip detector ever built. The design, construction and expected performance of the CMS Tracker is reviewed in the following.

physics.ins-det

W Physics at LEP

In five years of operation (1996-2000) the four LEP2 experiments collected roughly 3 fb-1 of data from e+e- collisions at centre-of-mass energies between 161 and 207 GeV, yielding a total of about 40000 W-pair events. The analysis of the LEP2 W-pair production rates and kinematics has allowed fundamental new measurements of the electroweak model to be performed, most notably: (i) the first determination of gauge boson self couplings, (ii) direct measurements of W decay couplings to all fermions, and (iii) a direct measurement of the W mass with a 40 MeV precision, comparable to hadron collider and indirect determinations.

hep-ex

Gauge Boson Self Couplings and four fermion final states at LEP

Four-fermion productions measured in the LEP2 data are reviewed. The total and differential cross-section yields represent the first clear evidence for the existence of gauge boson self couplings, in support of the non-abelian SU(2)xU(1) structure of the electroweak model, at the percent level.

hep-ex

Gaugino searches and constraints on supersymmetry

The negative outcome of gaugino searches at LEP has been one of the most disappointing results for fans of supersymmetric models. In the framework of minimal supersymmetric models with GUT unification assumptions, the combined absence of supersymmetry and Higgs signals in the LEP data, sets stringent constraints on the models parameter space, and lower limits on the mass of the lightest neutralino and of other supersymmetric particles. All limits are given at 95% Confidence Level.

hep-ex

Four-fermion final states in e+e- collisions at LEP2

The measurements of four-fermion production rates performed at LEP2 in e+e- collisions at centre-of-mass energies ranging from 161 to 209 GeV are presented. The focus is put on processes that involve the production and decay of W or Z electroweak bosons. Results on W decay rates and couplings are also discussed.

hep-ex

W-pair production at LEP

We review here the measurements of W-pair production and W decay rates performed by the four LEP experiments at ECM from 161 to 209 GeV, and their relevance in support of the standard electroweak model.

hep-ex