scholarly journals Jet angularities in Z+jet production at the LHC

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Simone Caletti ◽  
Oleh Fedkevych ◽  
Simone Marzani ◽  
Daniel Reichelt ◽  
Steffen Schumann ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Transverse Momentum ◽  
Parton Shower ◽  
Phenomenological Study ◽  
State Of The Art ◽  
Leading Order ◽  
Associate Production ◽  
Fixed Order ◽  
The Impact ◽  
Logarithmic Accuracy

Abstract We present a phenomenological study of angularities measured on the highest transverse-momentum jet in LHC events that feature the associate production of a Z boson and one or more jets. In particular, we study angularity distributions that are measured on jets with and without the SoftDrop grooming procedure. We begin our analysis exploiting state-of-the-art Monte Carlo parton shower simulations and we quantitatively assess the impact of next-to-leading order (NLO) matching and merging procedures. We then move to analytic resummation and arrive at an all-order expression that features the resummation of large logarithms at next-to-leading logarithmic accuracy (NLL) and is matched to the exact NLO result. Our predictions include the effect of soft emissions at large angles, treated as a power expansion in the jet radius, and non-global logarithms. Furthermore, matching to fixed-order is performed in such a way to ensure what is usually referred to as NLL′ accuracy. Our results account for realistic experimental cuts and can be easily compared to upcoming measurements of jet angularities from the LHC collaborations.

THE IMPACT OF LO, NLO AND NNLO FOR THE HIGGS SEARCHING AT $\sqrt{s} = 7$ TeV OF LHC

2010 ◽  
Vol 25 (36) ◽  
pp. 3027-3031
Author(s):  
JIAN WANG ◽  
GUOMING CHEN ◽  
WEIMIN WU
Keyword(s):  
Monte Carlo ◽  
Cross Section ◽  
Higgs Mass ◽  
Monte Carlo Generator ◽  
Final States ◽  
Leading Order ◽  
Analysis Process ◽  
Signal Rate ◽  
Monte Carlo Studies ◽  
The Impact

Most of current Monte Carlo studies on the Higgs searching are based on LO, or NLO calculation. However, in recent years, the next-to-next-to-leading order (NNLO) corrections have been computed for some physics process, and found that the cross section increases the kinematics changes. As the results, the analysis results could be impacted by these high order QCD corrections. We use standard Monte Carlo generator for LO, as well as MC@NLO for NLO and ResBos for NNLO at 7 TeV of LHC to evaluate this impact for physics channel of the Higgs, mass at 165 GeV, to WW, then W decay to lepton and neutrino as the final states. We found the signal rate could be effected by ratio of 1:2.6:3.4 for LO, NLO and NNLO using the same standard H→WW→lνlν searching analysis process.6

scholarly journals 3-D TCAD Monte Carlo Device Simulator: State-of-the-art FinFET Simulation

2021 ◽  
Vol 16 (2) ◽  
pp. 1-11
Author(s):  
Gabriela Firpo Furtado ◽  
Vinícius Valduga de Almeida Camargo ◽  
Dragica Vasileska ◽  
Gilson Inácio Wirth
Keyword(s):  
Monte Carlo ◽  
Phonon Scattering ◽  
State Of The Art ◽  
Real Space ◽  
Material System ◽  
Comprehensive Description ◽  
Pure Silicon ◽  
Ion Interactions ◽  
The Impact ◽  
Gate Work Function

This work presents a comprehensive description of an in-house 3D Monte Carlo device simulator for physical mod-eling of FinFETs. The simulator was developed to consider var-iability effects properly and to be able to study deeply scaled devices operating in the ballistic and quasi-ballistic regimes. The impact of random dopants and trapped charges in the die-lectric is considered by treating electron-electron and electron-ion interactions in real-space. Metal gate granularity is in-cluded through the gate work function variation. The capability to evaluate these effects in nanometer 3D devices makes the pre-sented simulator unique, thus advancing the state-of-the-art. The phonon scattering mechanisms, used to model the transport of electrons in pure silicon material system, were validated by comparing simulated drift velocities with available experi-mental data. The proper behavior of the device simulator is dis-played in a series of studies of the electric potential in the device, the electron density, the carrier's energy and velocity, and the Id-Vg and Id-Vd curves.

scholarly journals SIMULATION OF Z BOSON pT SPECTRUM AT TEVATRON BY LEADING-ORDER EVENT GENERATORS

2010 ◽  
Vol 25 (36) ◽  
pp. 3047-3059 ◽  
Author(s):  
SHIGERU ODAKA
Keyword(s):  
Transverse Momentum ◽  
Z Boson ◽  
Parton Shower ◽  
Event Generator ◽  
Boson Production ◽  
Proper Solution ◽  
Leading Order

We show that the transverse momentum (pT) spectrum of Z boson production measured at Fermilab Tevatron can be well reproduced by leading-order event generators if Z + 1 jet processes are included with a proper solution for the double-count problem and if the parton shower (PS) branch kinematics are defined appropriately. The choice of the PS evolution variable does not definitely determine the low-pT behavior. Our new event generator employing the limited leading-log (LLL) subtraction and a built-in leading-log PS reproduces the spectrum very well, not only in large pT regions but also at low pT down to pT = 0.

scholarly journals Extraction of partonic transverse momentum distributions from semi-inclusive deep-inelastic scattering, Drell-Yan and Z-boson production

2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Alessandro Bacchetta ◽  
Filippo Delcarro ◽  
Cristian Pisano ◽  
Marco Radici ◽  
Andrea Signori
Keyword(s):  
Transverse Momentum ◽  
Inelastic Scattering ◽  
Deep Inelastic Scattering ◽  
Z Boson ◽  
Boson Production ◽  
High Transverse Momentum ◽  
Momentum Distributions ◽  
Fixed Order ◽  
Global Fit ◽  
Logarithmic Accuracy

Abstract We present an extraction of unpolarized partonic transverse momentum distributions (TMDs) from a simultaneous fit of available data measured in semi-inclusive deep-inelastic scattering, Drell-Yan and Z boson production. To connect data at different scales, we use TMD evolution at next-to-leading logarithmic accuracy. The analysis is restricted to the low-transverse-momentum region, with no matching to fixed-order calculations at high transverse momentum. We introduce specific choices to deal with TMD evolution at low scales, of the order of 1 GeV2. This could be considered as a first attempt at a global fit of TMDs.

scholarly journals On the W&Y interpretation of high-energy Drell-Yan measurements

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Riccardo Torre ◽  
Lorenzo Ricci ◽  
Andrea Wulzer
Keyword(s):  
Monte Carlo ◽  
Differential Cross Section ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Differential Cross ◽  
High Energy ◽  
New Physics ◽  
Leading Order ◽  
Theoretical Predictions ◽  
The Impact

Abstract High-energy neutral and charged Drell-Yan differential cross-section measurements are powerful probes of quark-lepton contact interactions that produce growing-with-energy effects. This paper provides theoretical predictions of the new physics effects at the Next-to-Leading order in QCD and including one-loop EW corrections at the single-logarithm accuracy. The predictions are obtained from SM Monte Carlo simulations through analytic reweighting. This eliminates the need of performing a scan on the new physics parameter space, enabling the global exploration of all the relevant interactions. Furthermore, our strategy produces consistently showered events to be employed for a direct comparison of the new physics predictions with the data, or to validate the unfolding procedure than underlies the cross-section measurements. Two particularly relevant interactions, associated with the W and Y parameters of EW precision tests, are selected for illustration. Projections are presented for the sensitivity of the LHC and of the HL-LHC measurements. The impact on the sensitivity of several sources of uncertainties is quantified.

scholarly journals Fixed-order and merged parton-shower predictions for WW and WWj production at the LHC including NLO QCD and EW corrections

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Stephan Bräuer ◽  
Ansgar Denner ◽  
Mathieu Pellen ◽  
Marek Schönherr ◽  
Steffen Schumann
Keyword(s):  
Cross Sections ◽  
Parton Shower ◽  
Higher Order ◽  
Order Effects ◽  
Leading Order ◽  
Combined Analysis ◽  
Fixed Order ◽  
Higher Order Effects ◽  
Inclusive Sample ◽  
Electroweak Corrections

Abstract First, we present a combined analysis of pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}} $$ → μ + v μ e − v ¯ e and pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}}\mathrm{j} $$ → μ + v μ e − v ¯ e j at next-to-leading order, including both QCD and electroweak corrections. Second, we provide all-order predictions for pp $$ \to {\mu}^{+}{v}_{\mu }{\mathrm{e}}^{-}{\overline{v}}_{\mathrm{e}}+ $$ → μ + v μ e − v ¯ e + jets using merged parton-shower simulations that also include approximate EW effects. A fully inclusive sample for WW production is compared to the fixed-order computations for exclusive zero- and one-jet selections. The various higher-order effects are studied in detail at the level of cross sections and differential distributions for realistic experimental set-ups. Our study confirms that merged predictions are significantly more stable than the fixed-order ones in particular regarding ratios between the two processes.

scholarly journals Next-to-leading-order QCD corrections and parton-shower effects for weakino+squark production at the LHC

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Julien Baglio ◽  
Gabriele Coniglio ◽  
Barbara Jäger ◽  
Michael Spira
Keyword(s):  
Production Process ◽  
Parton Shower ◽  
Leading Order ◽  
Hadron Colliders ◽  
Perturbative Calculations ◽  
The Real ◽  
Decay Products ◽  
Production Processes ◽  
Fixed Order ◽  
Real Emission

Abstract We present a calculation of the next-to-leading order QCD corrections to weakino+squark production processes at hadron colliders and their implementation in the framework of the POWHEG-BOX, a tool for the matching of fixed-order perturbative calculations with parton-shower programs. Particular care is taken in the subtraction of on-shell resonances in the real-emission corrections that have to be assigned to production processes of a different type. In order to illustrate the capabilities of our code, representative results are shown for selected SUSY parameter points in the pMSSM11. The perturbative stability of the calculation is assessed for the pp →$$ {\tilde{\upchi}}_1^0{\tilde{d}}_L $$ χ ˜ 1 0 d ˜ L process. For the squark+chargino production process pp →$$ {\upchi}_1^{-}{\tilde{u}}_L $$ χ 1 − u ˜ L distributions of the chargino’s decay products are provided with the help of the decay feature of PYTHIA 8.

scholarly journals Measurement of b-quark fragmentation properties in jets using the decay B± → J/ψK± in pp collisions at $$ \sqrt{s} $$ = 13 TeV with the ATLAS detector

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
◽  
G. Aad ◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Transverse Momentum ◽  
Parton Shower ◽  
Atlas Detector ◽  
Pp Collisions ◽  
Radius Parameter ◽  
Quark Fragmentation ◽  
B Quark

Abstract The fragmentation properties of jets containing b-hadrons are studied using charged B mesons in 139 fb−1 of pp collisions at $$ \sqrt{s} $$ s = 13 TeV, recorded with the ATLAS detector at the LHC during the period from 2015 to 2018. The B mesons are reconstructed using the decay of B± into J/ψK±, with the J/ψ decaying into a pair of muons. Jets are reconstructed using the anti-kt algorithm with radius parameter R = 0.4. The measurement determines the longitudinal and transverse momentum profiles of the reconstructed B hadrons with respect to the axes of the jets to which they are geometrically associated. These distributions are measured in intervals of the jet transverse momentum, ranging from 50 GeV to above 100 GeV. The results are corrected for detector effects and compared with several Monte Carlo predictions using different parton shower and hadronisation models. The results for the longitudinal and transverse profiles provide useful inputs to improve the description of heavy-flavour fragmentation in jets.

scholarly journals Azimuthal correlations of high transverse momentum jets at next-to-leading order in the parton branching method

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
M. I. Abdulhamid ◽  
M. A. Al-Mashad ◽  
A. Bermudez Martinez ◽  
G. Bonomelli ◽  
I. Bubanja ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Cross Section ◽  
Parton Shower ◽  
Good Description ◽  
Leading Order ◽  
High Transverse Momentum ◽  
Azimuthal Correlation ◽  
Azimuthal Correlations ◽  
The Matrix ◽  
Good Agreement

AbstractThe azimuthal correlation, $$\Delta \phi _{12}$$ Δ ϕ 12 , of high transverse momentum jets in pp collisions at $$\sqrt{s}=13$$ s = 13  TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower. A very good description of the cross section as a function of $$\Delta \phi _{12}$$ Δ ϕ 12 is observed. In the back-to-back region of $${\Delta \phi _{12}}\rightarrow \pi $$ Δ ϕ 12 → π , a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in $$\alpha _\mathrm {s}$$ α s , and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. The $$\Delta \phi _{12}$$ Δ ϕ 12 measurements are also compared with predictions using MCatNLO together Pythia8, illustrating the importance of details of the parton shower evolution.

scholarly journals Status of the BabaYaga event generator

2019 ◽  
Vol 218 ◽  
pp. 07004 ◽  
Author(s):  
Carlo M. Carloni Calame ◽  
Guido Montagna ◽  
Oreste Nicrosini ◽  
Fulvio Piccinini
Keyword(s):  
Monte Carlo ◽  
High Precision ◽  
Parton Shower ◽  
Monte Carlo Event ◽  
Event Generator ◽  
Leading Order ◽  
Monte Carlo Event Generator ◽  
The Status ◽  
Higher Order Corrections ◽  
Theoretical Accuracy

The Monte Carlo event generator BabaYaga has been developed for high precision simulation of QED processes (e+e−→ e+ e− , e+e−→ µ+µ− and e+e−→ γγ) at flavour factories, chiefly for luminometry purposes, with an estimated theoretical accuracy at the 0.1% level or better. QED radiative corrections are included by means of a Parton Shower in QED matched with exact next-to-leading order corrections to reach the required accuracy. The latter is assessed by means of consistent comparisons to independent calculations and an estimate of the size of missing higher-order corrections. The main theoretical framework is overviewed and the status of the generator is summarized.

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