# Kick-off meeting of the LHCPhenoNet Initial Training Network

Europe/Brussels
Sala Ausias March (Centre Cultural Bancaixa, Valencia)

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Description

The goal of the meeting is to review and to discuss the state-of-the-art and future developments in the research field of higher order perturbative corrections in the Standard Model and beyond, with emphasis on phenomenology at the LHC, and the development of customized open source software for precision physics at colliders. This is the first meeting organized with the support of the LHCPhenoNet Initial Training Network, but is also open to non-members of the network.

Video of the public talk by David Kaplan (Johns Hopkins University)

Participants
• Agustin Sabio Vera
• Andreas v. Manteuffel
• Benedikt Biedermann
• Carsten Schneider
• Clara Salas HernÁndez
• Cristina Merino-FernÁndez
• Damiano Tommasini
• Daniel de Florian
• David Hare
• David Kaplan
• Edmond BERGER
• Francisco Campanario
• Fulvio Piccinini
• Gabor Somogyi
• Gavin Salam
• German Rodrigo
• Giancarlo Ferrera
• Grigorios Chachamis
• Guido Montagna
• Ignazio Scimemi
• Isabella Bierenbaum
• Janusz Gluza
• Joey Huston
• Johannes Bluemlein
• Juan Rojo
• Kouhei Hasegawa
• Lisa Hartgring
• Luca BarzÈ
• Manuel Kauers
• Marcel Vos
• Maria Vittoria Garzelli
• Marta Felcini
• Martin Hentschinski
• Matteo Cacciari
• Mauro Moretti
• Michal Deak
• Michelangelo mangano
• Miguel GarcÍa EchevarrÍa
• Miguel Nebot
• Nikolai Zerf
• Oleksandr Pavlyk
• Olga Shekhovtsova
• Pascal Nef
• Petros Draggiotis
• Raoul Rontsch
• Riccardo Torre
• Rikkert Frederix
• Rob Knegjens
• Robert Schabinger
• Roman Stainko
• Sebastian Buchta
• Susana Cabrera
• Sven-Olaf Moch
• Thomas Gehrmann
• Thomas Reiter
• Tom Melia
• Valery Yundin
• Vittorio del Duca
• Xin-Qiang Li
• Zoltan Trocsanyi
Support
• Monday, 31 January
• 19:00 21:00
Registration and Welcome 2h Hotel Astoria (Hotel Astoria)

### Hotel Astoria

#### Hotel Astoria

• Tuesday, 1 February
• 09:00 09:10
Registration 10m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 09:10 09:30
Welcome Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 09:10
Welcome 20m
by Pedro M. Carrasco (Research and Scientific Policy Vicerector, UVEG) and José Pío Beltrán (Valencian Institutional Coordinator, CSIC)
Speakers: José Pío BeltrÁn (CSIC), Pedro M. Carrasco (UVEG)
• 09:30 10:15
Tuesday Morning I Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Michelangelo L. MANGANO (CERN)
• 09:30
Overview of last results from ATLAS 45m
Speaker: Joey Huston
• 10:15 10:45
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 10:45 13:00
Tuesday Morning II Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Gavin SALAM (LPTHE)
• 10:45
A view from the top 30m
In this talk I'll give an overview of the latest results at Tevatron related to top quark physics and give my ideas on the analyses and theoretical improvements needed to address the few results that are couple of sigma away from SM expectations
Speaker: Rikkert Frederix
• 11:15
Two-loop corrections to top-quark pair 30m
Two-loop corrections to top-quark pair production At LHC, top-quark pair production is an important process to test the Standard Model and search for new physics. I discuss the analytical calculation of two-loop QCD corrections to this process.
Speaker: Andreas V. Manteuffel
• 11:45
NNLO jet cross sections via local subtraction 30m
We give a status report on the construction of a general, local subtraction scheme for evaluating jet cross sections at NNLO in perturbative QCD. In particular, recent results on the evaluation of integrated approximate cross sections are presented.
Speaker: Gabor SOMOGYI
• 12:15
Higgs production and fixed-target DIS data 30m
Speaker: Sven-Olaf Moch
• 13:00 15:00
Lunch 2h Hotel Astoria (Hotel Astoria)

### Hotel Astoria

#### Hotel Astoria

• 15:00 16:00
Tuesday Afternoon I Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Mauro MORETTI (Universitá di Ferrara)
• 15:00
Showered events at NLO accuracy: case of t tbar b bbar final states 30m
We compute the production cross section of a simultaneous t-anti-t pair and a b-anti-b pair at hadron colliders at next-to-leading order accuracy matched with parton shower algorithms to make predictions at the hadron level. The parton shower allows for including the decay of the top quarks at the leading order accuracy. We use a framework based on three well established numerical codes, the POWHEG-BOX, used for the calculation of the cross section, HELAC, which generates the matrix elements for the Born-level, real emission and the virtual part, and finally a parton shower program, such as PYTHIA or HERWIG, which generate the parton-shower and hadronization.
Speaker: Zoltan Trocsanyi
• 15:30
Showered events at NLO accuracy: production of a top quark pair in association with a jet 30m
We compute the production cross section of a top-antitop pair in association with a jet at hadron colliders at next-to-leading order accuracy matched with parton shower algorithms to make predictions at the hadron level. The parton shower allows for including the decay of the top quarks at the leading order accuracy. We use a framework based on three well established numerical codes, the POWHEG-BOX, used for the calculation of the cross section, HELAC, which generates the matrix elements for the Born-level, real emission and thevirtual part, and finally a parton shower program, such as PYTHIA or HERWIG, which generate the parton-shower and hadronization.
• 16:00 16:30
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 16:30 18:00
Tuesday Afternoon II Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 16:30
Discovery potential of top-partners in a realistic composite Higgs model with early LHC data 30m
Composite Higgs models provide a natural, non-supersymmetric solution to the hierarchy problem. The large top mass is explained with the introduction of one or more multiplets of new quarks, which could be well within the reach of the early LHC data. We implement the model in MadGraph and analyse in detail the collider signatures that these new quarks can produce. The discovery potential of the model in multi-lepton final states is discussed. Moreover, we outline a new method to reconstruct the mass of the introduced charge 5/3 top-partners.
Speaker: Pascal Nef
• 17:00
BSM-GUT particles at LHC 30m
Speaker: Janusz Gluza
• 17:30
Double Parton Scattering at the LHC 30m
Speaker: Edmond Berger
• 18:00 19:00

#### Centre Cultural Bancaixa, Valencia

• 19:00 21:30
Public Talk Salón

### Salón

#### Centre Cultural Bancaixa, Valencia

Convener: Gavin SALAM (LPTHE)
• 19:30
<a href="http://www.lhcphenonet.eu/outreach">The Large Hadron Collider: Living with the Uncertainty Principle (Public talk)</a> 1h
The largest scientific machine ever constructed, the Large Hadron Collider outside of Geneva, was switched on just a few months ago. The data from this experiment could have a dramatic effect on our beliefs about the origin of matter, the properties of space and time, and the mysterious contents of the Universe. In this talk, I will describe the Large Hadron Collider and explain why we do such experiments. I will also talk about the underlying rules of Nature, governed by Quantum Field Theory, and describe some of the fantastical things we hope to see: dark matter, supersymmetry, or extra dimensions. Finally, I will describe the historical context of this moment in science and the uncertainty of the future direction of fundamental physics.
Speaker: David Kaplan
• Wednesday, 2 February
• 09:15 10:30
Wednesday Morning I Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Zoltan TROCSANYI (University of Debrecen)
• 09:15
Higgs searches in the light of latest theoretical and experimental developments 45m
Speaker: Marta Felcini
• 10:00
NLO QCD corrections to processes with multiple electroweak bosons &amp; Higgs + jj via Gluon Fusion 30m
Speaker: Francisco Campanario
• 10:30 11:00
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 11:00 13:00
Industry Partners and Briefing Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Johannes BLÜMLEIN (DESY Zeuthen)
• 11:00
Projects for intern students at Maplesoft 30m
Speaker: David Hare
• 11:30
Mathematica opportunities 30m
Speaker: Oleksandr Pavlyk
• 12:00
Programming Projects from RISC Software Gmbh 30m
Speaker: Roman Stainko
• 12:30
LHCPhenoNet briefing 20m
Speaker: German RODRIGO
• 13:00 15:00
Lunch 2h Hotel Astoria (Hotel Astoria)

### Hotel Astoria

#### Hotel Astoria

• 15:00 16:00
Wednesday Afternoon I Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Fulvio PICCININI (INFN Pavia)
• 15:00
What a rook can do on a twelve dimensional chess board 30m
The guess'n'prove problem solving paradigm consists of two steps: first, a solution is "guessed" empirically based on inspection of special cases and/or other dirty and non-rigorous tricks. Only in the second step, a completely rigorous formal proof of the potential solution found in the first step is derived. Computer algebra provides tools for supporting both steps: the guessing part and the proving part. There are cases where the computational cost for proving are much higher than for guessing a solution. One may then be content with an uncertified solution, because in practice, guessed results are correct anyway. In the talk we will illustrate the difference between rigorous and not-so-rigorous-but-nevertheless-trustworthy computations with a combinatorial counting problem on which we recently worked together with D. Zeilberger.
Speaker: Manuel Kauers
• 15:30
Multi-Summation for Particle Physics 30m
We present up to date summation technologies that assist in the task to evaluate 3-loop massive single scale Feynman integrals with operator insertation. Special emphasis is put on new evaluations that are relevant for the the computations at the LHC.
Speaker: Carsten Schneider
• 16:00 16:30
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 16:30 18:30
Wednesday Afternoon II Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Sven-Olaf MOCH (DESY Zeuthen)
• 16:30
Parton distributions for precision LHC phenomenology 30m
The precision determination of parton distributions is an essential ingredient for LHC phenomenology. In this talk we review recent progress in the NNPDF determnation of parton distributions. We estimate theoretical uncertainties in LHC observables arising from heavy quark mass effects. We show how to use Bayesian inference to determine the impact of new data into PDFs without the need of refitting. Finally, we discuss the impact of PDFs on the interpretation of the first LHC measurements and exclusion limits, and examine how LHC data can be used to further constrain PDFs in a new kinematical regime.
Speaker: Juan Rojo
• 17:00
Giant K factors 30m
Speaker: Gavin Salam
• 17:30
A comparative study of small x Monte Carlos with and without QCD coherence effects 30m
We compare two Monte Carlo implementations of resummation schemes for the description of parton evolution at small values of Bjorken x. One of them if based on the BFKL evolution equation and generates fully differential parton distributions in momentum space making use of reggeized gluons. The other one is based on the CCFM partonic kernel where QCD coherence effects are introduced. It has been argued that both approaches agree with each other in the x → 0 limit. We show that this is not the case for azimuthal angle dependent quantities since at high energies the BFKL approach is dominated by its zero conformal spin component while the CCFM gluon Green function receives contributions from all conformal spins even at very small x.
Speaker: Michal Deak
• 18:00
Transverse-momentum resummation in Drell-Yan process at NNLL accuracy. 30m
We consider the transverse-momentum (q_T) distribution of Drell--Yan lepton pairs produced in hadron collisions. At small values of q_T, we resum the logarithmically-enhanced perturbative QCD contributions up to next-to-next-to-leading logarithmic accuracy. At intermediate and large values of q_T, we consistently combine resummation with the known next-to-leading order perturbative result. All perturbative terms up to order alpha_S^2 are included in our computation. We show the scale dependence of the results which allows us to estimate the corresponding perturbative uncertainty. We present a preliminary comparison with Tevatron Run II data and some illustrative results for the LHC.
Speaker: Giancarlo Ferrera
• 18:30 19:30

#### Centre Cultural Bancaixa, Valencia

• 20:15 23:30
Social Dinner 3h 15m Buses from Hotel Ingles

### Buses from Hotel Ingles

#### Centre Cultural Bancaixa, Valencia

Buses will leave at 20:15 from Hotel Inglés

• Thursday, 3 February
• 09:30 10:30
Thursday Morning I Sala Lluis Vives

### Sala Lluis Vives

#### Centre Cultural Bancaixa, Valencia

Convener: Thomas GEHRMANN (Universität Zürich)
• 09:30
Multijet events and hard diffractive scattering in the Regge limit with collinear corrections 30m
I will review the status of the application of the BFKL approach to LHC phenomenology.
Speaker: Agustin Sabio Vera
• 10:00
3-loop heavy flavor corrections to Deep-Inelastic Scattering 30m
Speaker: Johannes Bluemlein
• 10:30 11:00
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 11:00 13:00
ESRs Session Sala

### Sala

#### Centre Cultural Bancaixa, Valencia

Convener: Daniel DE FLORIAN (U. Buenos Aires)
• 11:00
The MHV-Lagrangian for electroweak gauge bosons 30m
Theoretical predictions at the LHC for processes involving many partons, for example the determination of the Higgs mass as well as possible signals of "New Physics", make the precise knowledge of scattering amplitudes necessary. The number of Feynman diagrams to calculate grows factorially with the number of external legs. Therefore, efficient techniques reducing the computing time are needed. Amongst these MHV amplitudes are a popular tool providing a neat way for the fast calculation of scattering amplitudes at tree level. Originally, the MHV amplitude was discovered during the study of pure Yang-Mills theory. The purpose of this talk is to show how to extend their usefulness towards the electroweak gauge boson sector
Speaker: Sebastian Buchta
• 11:30
Resonances at the Early LHC 30m
Adopting a phenomenological approach I discuss the possibility to observe new resonances in the early stage of the LHC. For simple parton luminosity reasons the gluon-gluon, quark-gluon and quark-quark production mechanisms are favored with respect to the quark-antiquark one at the LHC. I show some predictions for the production of a scalar in the gluon-gluon channel and a fermion in the quark-gluon channel. I compare these predictions with the recent results from ATLAS and CMS and I also discuss the importance of the final states containing at least one photon. Finally I compare these favored channels with the case of a "weakly constrained" W' produced in the quark-antiquark channel.
Speaker: Riccardo Torre
• 12:00
One loop tensor reduction program PJFRY 30m
Speaker: Valery Yundin
• 12:30
AutoDipole and the application to LHC 30m
Catani-Seymour dipole subtraction is a general and practical procedure for QCD NLO prediction. We automated it in the computer packages, AutoDipole for SM process and SuperAutoDipole for MSSM processes. The features of the packages and an application to LHC are shown.
Speaker: Kouhei Hasegawa
• 13:00 15:00
Lunch 2h Hotel Astoria (Hotel Astoria)

### Hotel Astoria

#### Hotel Astoria

• 15:00 16:00
Thursday Afternoon I Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Janusz GLUZA (Uniwersytet Śląski)
• 15:00
One-Loop Calculations with Golem and Samurai 30m
The results of the NLO corrections for the production of two b-quark pairs at the LHC are discussed. In our calculation we followed a Feynman diagrammatic approach using automated tools such as Golem, Samurai and MadGraph/MadEvent and MadDipole. The improvement of accuracy through our results can have an important impact on the prospects of MSSM Higgs searches in the 4b channel.
Speaker: Thomas Reiter
• 15:30
WW+2 jets at NLO using generalised D-dimensional unitarity 30m
I shall describe the calculation, which uses the framework of generalised D-dimensional unitarty, and present results for this process at the LHC.
Speaker: Tom Melia
• 16:00 16:30
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 16:30 18:30
Thursday Afternoon II Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Matteo CACCIARI (LPTHE)
• 16:30
One-loop Gluon Amplitudes with Generalised Unitarity 30m
The evaluation of colour-ordered n-gluon amplitudes at one-loop order in pure Yang-Mills theory is presented. Thereby the recently developed technique of generalised unitarity is used. Our program can handle arbitrary numbers of external gluons. Running in double precision one gets reliable results for up to 14 gluons with only a small fraction of events requiring a re-evaluation using extended floating point arithmetic.
Speaker: Benedikt Biedermann
• 17:00
Feynman´s Tree Theorem & Loop-Tree Dualities 30m
Due to the start of the LHC, perturbative calculations for scattering processes with a large number of particles in the final state and to a very high precision are needed, leading to Feynman diagrams with a large number of external legs and many loops. In addition to the calculation of diagrams by applying Feynman parameters, various unitarity and recursive methods have been successfully used in the past years to address this issue and to calculate scattering amplitudes for multi-particle processes up to next-to-leading order (NLO). In this talk, I will present the Duality Method, which provides a cutting-relation to calculate loop diagrams in a similar manner like the corresponding real-radiation tree diagrams. I will introduce this method in detail and show how it can be extended to higher loop orders beyond NLO.
Speaker: Petros Drangiotis
• 17:30
Amplitudes and Wilson loops in N=4 SYM 30m
Speaker: Vittorio Del Duca
• 18:00
On the Rational part of 1-loop amplitudes 30m
Speaker: Maria Vittoria GARZELLI
• Friday, 4 February
• 09:00 10:30
Friday Morning I Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Edmond BERGER (ANL)
• 09:00
Resonant particle production at the LHC 30m
We present an effective-theory inspired method to include off-shell effects for the production and subsequent decay of heavy unstable particles at the LHC.
• 09:30
Mellin-Barnes techniques and gauge boson pair production to NNLO 30m
Speaker: Grigorios Chachamis
• 10:00
The high energy limit of QCD: kT-factorization and exclusive production cross-sections at the LHC 30m
We investigate LHC production cross-sections, using NLO BFKL resummation and kT-factorization. As a particular process we consider the completely differential production of heavy flavors. Unintegrated gluon densities are constructed as a convolution of BFKL Green's function and non-perturbative proton impact factor for which we study different models. The whole setup is presented in kT space, which allows to implement our result directly into the NLO BFKL Monte Carlo event generator. We further explore the possible use of the high energy QCD effective action for the determination of (NLO) impact factors and production vertices. In particular we present a regularization mechanism and a matching procedure which can be used for such calculations.
Speaker: Martin HENTSCHINSKI
• 10:30 11:00
Coffee break 30m Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

• 11:00 13:00
Friday Morning II Sala Ausias March

### Sala Ausias March

#### Centre Cultural Bancaixa, Valencia

Convener: Vittorio DEL DUCA (INFN LNF)
• 11:00
Gauge Boson production at NNLO in hadronic collisions 30m
Speaker: Daniel De Florian
• 11:30
Higgs boson production in gluon fusion to NNLO in the MSSM 30m
We consider the Higgs boson production in the gluon-fusion channel to next- to-next-to-leading order within the Minimal Supersymmetric Standard Model. In particular, we present analytical results for the matching coefficient of the effective theory and study its influence on the total production cross section in the limit where the masses of all MSSM particles coincide. For supersymmetric masses below 500 GeV we observe a significant enhancement of the Standard Model cross section, the K factor, however, changes only marginally.
Speaker: Nikolai Zerf
• 12:00
MSR: The improvement of QCD series with a new renormalization scheme 30m
Perturbative QCD results in the MSbar scheme can be dramatically improved by switching to a scheme that accounts for the dominant power law dependence on the factorization scale in the operator product expansion. We introduce the MSR scheme'' which achieves this in a Lorentz and gauge invariant way. The MSR scheme has a very simple relation to MSbar, and can be easily used to reanalyze MSbar results. I will show the essential part and latest developments and some phenomenological applications of the new scheme.
Speaker: Ignazio Scimemi
• 12:30
Soft-Collinear Effective Theory: From the LHC to RHIC 30m
Recent developments in Soft-Colinear Effective Theory are discussed with applications to high-energy processes relevant at the LHC and RHIC.