scholarly journals Mitigating Large Background in Jet Substructure Observables

2020 ◽  
Vol 235 ◽  
pp. 05002
Author(s):  
Daekyoung Kang ◽  
Yang-Ting Chien ◽  
Kyle Lee ◽  
Yiannis Makris
Keyword(s):  
Jet Physics ◽  
Effective Theory ◽  
Soft Particle ◽  
Jet Substructure ◽  
Mass Measurements ◽  
New Approach ◽  
Soft Collinear Effective Theory ◽  
Pile Up ◽  
Theoretical Results ◽  
Good Agreement

We discuss a new approach for jet physics analysis by using subtraction between cumulants of jet substructure observables. The subtracted cumulants are insensitive to soft-particle background uncorrelated with the hard process and allow comparisons between theoretical results and experimental measurements without the complication of soft background like underlying and pile-up events. We find our method using jet mass cumulants efficiently eliminates the background in Monte Carlo simulations and ATLAS jet mass measurements and they show a good agreement with our analytic calculations performed using soft-collinear effective theory.

Soft-Collinear Effective Theory

2020 ◽  
pp. 307-361 ◽  
Author(s):  
Thomas Becher
Keyword(s):  
Cross Sections ◽  
Vector Current ◽  
Jet Physics ◽  
Effective Theory ◽  
Event Shape ◽  
Sudakov Form Factor ◽  
Shape Variable ◽  
Soft Collinear Effective Theory ◽  
Jet Cross Sections ◽  
Event Shape Variable

The lectures that appear within this chapter provide an introduction to soft-collinear effective theory (SCET). It begins by discussing resummation for soft-photon effects in QED, including soft photons in electron–electron scattering and the expansion of loop integrals and the method of regions event-shape variables. It then covers SCET specifically, including the method of regions for the Sudakov form factor, effective Lagrangians, the vector current in SCET, and resummation by renormalization group (RG) evolution. It covers applications of SCET in jet physics, describes the characteristic feature in jet processes of Sudakov logarithms, and discusses factorization for the event-shape variable thrust and factorization and resummation for jet cross sections.

Using Pyroelectric Sensors to Detect Continuous Infrared Radiation

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
Mozhde Heydarianasl ◽  
Mohd Fua’ad Rahmat
Keyword(s):  
Infrared Radiation ◽  
Electrical Circuit ◽  
Thermo Electric ◽  
New Approach ◽  
Digital Oscilloscope ◽  
Mechanical Parts ◽  
Infrared Rays ◽  
Pyroelectric Sensors ◽  
Theoretical Results ◽  
Good Agreement

This paper focuses on an optimized method for detecting continuous infrared rays make use of Pyroelectric devices. Now, Pyroelectric devices are usually very sensitive to changes in infrared radiation in the presence of an object when transfers or radiation is connected or disconnected. In this new approach, the thermo-electric cooler is employed to active temperature sensors instead of conventional modulation. They use mechanical parts, which are complex and un-reliable. The most of the sensor consists of a number of important restrictions, which are expected to be eliminated by a new method in this study. To simulate the thermal and electrical behavior of the detector, the equivalent electrical circuit is needed that will be proposed.The practical results of Pyroelectric sensor are sent to a computer by a digital oscilloscope, and then they are monitored and analyzed. After that, the model is simulated with MATLAB software. Finally, practical and theoretical results compared with each other and a good agreement of them is shown and confirms the validity of the model.

scholarly journals Recent progress on jet substructure theory

2020 ◽  
Vol 235 ◽  
pp. 05001
Author(s):  
Zhong-Bo Kang
Keyword(s):  
Effective Theory ◽  
Jet Substructure ◽  
Coupling Constant ◽  
Proton Proton ◽  
Proton Collisions ◽  
Qcd Factorization ◽  
Soft Collinear Effective Theory ◽  
Logarithmic Corrections ◽  
Inclusive Jet Production ◽  
Proton Proton Collisions

In these proceedings, we review recent theoretical progress on jet substructure at the colliders. Focusing on two observables – jet mass and groomed jet radius, we perform theoretical computations for jets measured in the single inclusive jet production in proton-proton collisions, pp → jet + X. We consider both standard ungroomed jets as well as soft-drop groomed jets. Within the Soft Collinear Effective Theory (SCET), we establish QCD factorization theorems which allow for the joint resummation of several classes of logarithmic corrections to all orders in the strong coupling constant. We present numerical results and compare with the available data from the LHC.

scholarly journals Beer mats make bad frisbees

2021 ◽  
Vol 136 (7) ◽  
Author(s):  
Johann Ostmeyer ◽  
Christoph Schürmann ◽  
Carsten Urbach
Keyword(s):  
Approximate Solution ◽  
High Speed ◽  
Center Of Mass ◽  
Effective Theory ◽  
High Speed Camera ◽  
Minimal Set ◽  
Crucial Effect ◽  
Forward Edge ◽  
Theoretical Results ◽  
Good Agreement

AbstractIn this article we show why flying and rotating beer mats, CDs, or other flat disks will eventually flip in the air and end up flying with backspin, thus, making them unusable as frisbees. The crucial effect responsible for the flipping is found to be the lift attacking not in the center of mass but slightly offset to the forward edge. This induces a torque leading to a precession towards backspin orientation. An effective theory is developed providing an approximate solution for the disk’s trajectory with a minimal set of parameters. Our theoretical results are confronted with experimental results obtained using a beer mat shooting apparatus and a high speed camera. Very good agreement is found.

scholarly journals Precise predictions for photon pair production matched to parton showers in GENEVA

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Simone Alioli ◽  
Alessandro Broggio ◽  
Alessandro Gavardi ◽  
Stefan Kallweit ◽  
Matthew A. Lim ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Pair Production ◽  
Higher Order ◽  
Photon Pair ◽  
Effective Theory ◽  
Parton Level ◽  
Soft Collinear Effective Theory ◽  
Additional Radiation ◽  
Monte Carlo Framework ◽  
Good Agreement

Abstract We present a new calculation for the production of isolated photon pairs at the LHC with $$ {\mathrm{NNLL}}_{{\mathcal{T}}_0}^{\prime } $$ NNLL T 0 ′ +NNLO accuracy. This is the first implementation within the Geneva Monte Carlo framework of a process with a nontrivial Born-level definition which suffers from QED singularities. Throughout the computation we use a smooth-cone isolation algorithm to remove such divergences. The higher-order resummation of the 0-jettiness resolution variable $$ {\mathcal{T}}_0 $$ T 0 is based on a factorisation formula derived within Soft-Collinear Effective Theory which predicts all of the singular, virtual and real NNLO corrections. Starting from this precise parton-level prediction and by employing the Geneva method, we provide fully showered and hadronised events using Pythia8, while retaining the NNLO QCD accuracy for observables which are inclusive over the additional radiation. We compare our final predictions to LHC data at 7 TeV and find good agreement.

scholarly journals Resummation of Jet Shapes and Extracting Properties of the Quark-Gluon Plasma

2015 ◽  
Vol 37 ◽  
pp. 1560047 ◽  
Author(s):  
Yang-Ting Chien
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Jet Quenching ◽  
Effective Theory ◽  
Proton Proton ◽  
Power Corrections ◽  
Soft Collinear Effective Theory ◽  
Jet Shapes ◽  
Good Agreement

Understanding the properties of the quark-gluon plasma (QGP) that is produced in ultra-relativistic nucleus-nucleus collisions has been one of the top priorities of the heavy ion program at the LHC. Energetic jets are produced and subsequently quenched in the collisions. Such jet quenching phenomena provide promising tools to probe the medium properties by studying the modification of jets due to the medium interactions. Significant modifications of jet shapes have been measured. In this talk we focus on the calculation of jet shapes in both proton-proton and lead-lead collisions using soft-collinear effective theory (SCET), with Glauber gluon interactions in the medium. Large logarithms in jet shapes are resummed at next-to-leading logarithmic (NLL) accuracy by the renormalization-group evolution between hierarchical jet scales. The medium interactions contribute as power corrections, and we calculate the modification of jet shapes at leading order in opacity with the static QGP model. Preliminary results are presented with good agreement with the recent CMS jet shape measurements.

scholarly journals Cutoff dependence of the thrust peak position in the dipole shower

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Robin Baumeister ◽  
Stefan Weinzierl
Keyword(s):  
Parton Shower ◽  
Peak Position ◽  
Effective Theory ◽  
Cutoff Value ◽  
Soft Collinear Effective Theory ◽  
Thrust Distribution ◽  
Cutoff Dependence ◽  
Analytic Computation ◽  
Good Agreement

AbstractWe analyse the dependence of the peak position of the thrust distribution on the cutoff value in the Nagy–Soper dipole shower. We compare the outcome of the parton shower simulations to a relation of the dependence from an analytic computation, derived within soft-collinear effective theory. We show that the result of the parton shower simulations and the analytic computation are in good agreement.

scholarly journals Numerical Solution of a Class of Predator-Prey Systems with Complex Dynamics Characters Based on a Sinc Function Interpolation Collocation Method

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-34
Author(s):  
Mingjing Du ◽  
Pengfei Ning ◽  
Yulan Wang
Keyword(s):  
Collocation Method ◽  
Complex Dynamics ◽  
Sinc Function ◽  
New Approach ◽  
Predator Prey ◽  
Prey System ◽  
Simulation Results ◽  
Pattern Formations ◽  
Theoretical Results ◽  
Good Agreement

Although many kinds of numerical methods have been announced for the predator-prey system, simple and efficient methods have always been the direction that scholars strive to pursue. Based on this problem, in this paper, a new interpolation collocation method is proposed for a class of predator-prey systems with complex dynamics characters. Some complex dynamics characters and pattern formations are shown by using this new approach, and the results have a good agreement with theoretical results. Simulation results show the effectiveness of the method.

QCD

2005 ◽  
Vol 20 (14) ◽  
pp. 3007-3020
Author(s):  
SEAN FLEMING
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
B Meson ◽  
Belle Collaboration ◽  
Meson Production ◽  
Effective Theory ◽  
Charmonium Production ◽  
Soft Collinear Effective Theory ◽  
Experimental Side ◽  
Theoretical Results

In this talk I review recent experimental and theoretical results in QCD. Since the topic is too vast to cover within given time constraints I choose to highlight some of the subjects that I find particularly exciting. On the experimental side I focus on measurements made at the Tevatron. Specifically jet production rates, and the cross section for B meson production. In addition I discuss an interesting measurement made by the Belle collaboration of double exclusive charmonium production. On the theory side I quickly review recent advances in computing hadronic cross sections at subleading order in perturbation theory. I then move on to soft-collinear effective theory. After a lightning review of the formalism I discuss recently published results on color-suppressed B → D decays.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

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