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BEGIN:VEVENT
SUMMARY:A new formulation of the loop-tree duality at higher loops
DTSTART;VALUE=DATE-TIME:20190912T123000Z
DTEND;VALUE=DATE-TIME:20190912T125500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512568@indico.cern.ch
DESCRIPTION:Speakers: Zoltán Szőr (Mainz University)\nRelating loop inte
grals to tree level objects goes back several decades to Feynman. In the p
ast ten years the loop-tree duality theorem was introduced\, which express
es $l$-loop integrals in terms of phase space integrals of sum of trees ob
tained from cutting $l$ internal propagators of the loop graph. In additio
n\, the uncut propagators gain a modified $i \\delta$-prescription\, named
dual propagators.\n\nIn my talk I present a new formulation of the loop-t
ree duality theorem for higher loop diagrams valid both for massless and m
assive cases. In this new framework one can go beyond loop-graphs and calc
ulate the integrand of loop-amplitudes as a weighted sum of tree graphs\,
which form a tree-like object. These objects can be computed efficiently v
ia recurrence relations.\n\nhttps://indico.cern.ch/event/783212/contributi
ons/3512568/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512568/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Renormalization schemes for mixing angles
DTSTART;VALUE=DATE-TIME:20190912T140000Z
DTEND;VALUE=DATE-TIME:20190912T142500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512545@indico.cern.ch
DESCRIPTION:Speakers: Ansgar Denner (Julius Max. Universitaet Wuerzburg (D
E))\nThe proper renormalization of mixing angles in quantum field theories
\nis a long-standing problem. It is relevant for the renormalization of th
e\nquark mixing matrix in the Standard Model and for various mixing\nscena
rios in theories beyond. In this talk we specifically consider\ntheories w
ith extended scalar sectors. We review existing renormalization\nschemes f
or mixing angles and introduce new ones based on on-shell\nconditions or s
ymmetry requirements such as rigid or background-field\ngauge invariance.
Considering in particular the renormalization of the\nmixing angles in the
Two-Higgs-Doublet Model and the Higgs-Singlet Extension\nof the Standard
Model\, we compare electroweak corrections\nwithin these models for a sele
ction of renormalization schemes.\n\nhttps://indico.cern.ch/event/783212/c
ontributions/3512545/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512545/
END:VEVENT
BEGIN:VEVENT
SUMMARY:QFT with FDR
DTSTART;VALUE=DATE-TIME:20190912T133000Z
DTEND;VALUE=DATE-TIME:20190912T135500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3519057@indico.cern.ch
DESCRIPTION:Speakers: Roberto Pittau (Universidad de Granada (ES))\nI disc
uss the latest developments of FDR in the context of Quantum Field Theory
calculations relevant for High Energy Physics phenomenology. In particular
\, I focus on NNLO computations and the use of FDR in connection to effect
ive QFTs.\n\nhttps://indico.cern.ch/event/783212/contributions/3519057/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3519057/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Loops from trees in four space-time dimensions
DTSTART;VALUE=DATE-TIME:20190912T130000Z
DTEND;VALUE=DATE-TIME:20190912T132500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512632@indico.cern.ch
DESCRIPTION:Speakers: William Javier Torres Bobadilla (IFIC CSIC-UV)\nIn o
rder to make predictions that can be compared with the results that the LH
C delivers\, there are several approaches to compare the experiment with t
he theory. It is known that to establish this comparison\, we cannot rely
on leading order (LO) calculations only. Hence\, we need to consider next-
to-leading order (NLO) contributions\, that are often understood as virtua
l and real. Although we know how to generate these contributions\, their e
valuation is not always straightforward. In particular\, because of the pr
esence of infinities\, UV and IR singularities. In this talk\, we elaborat
e on their local cancellation by means of the four-dimensional unsubtracti
on scheme\, which stems from the loop-tree duality theorem. To illustrate
this method\, we show the decay of H->γγ at LO and NLO\, for which\, aft
er properly cancelling the infinities at integrand level\, by performing l
ocal UV renormalisation and local IR cancellation\, we are allowed to inte
grate in four-dimensions.\nFinally\, we analyse the singular structure of
scattering amplitudes directly in the loop momentum space\, which is parti
cularly interesting to characterise unitarity and anomalous thresholds for
specific kinematical configurations.\n\nhttps://indico.cern.ch/event/7832
12/contributions/3512632/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512632/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Second order QCD corrections to the g + g → H + H four-point amp
litude
DTSTART;VALUE=DATE-TIME:20190912T140000Z
DTEND;VALUE=DATE-TIME:20190912T142500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512615@indico.cern.ch
DESCRIPTION:Speakers: Pulak Banerjee (Paul Scherrer Institut)\nIn this tal
k\, I present the computation of the two loop massless QCD corrections to
the four-point amplitude $g + g → H + H$ (arXiv:1809.05388) resulting fr
om effective operator insertions that describe the interaction of a Higgs
boson with gluons in the infinite top quark mass limit. This amplitude is
an essential ingredient to the third-order QCD corrections to Higgs boson
pair production. Our results are implemented in a numerical code that can
be used for further phenomenological studies.\n\nhttps://indico.cern.ch/ev
ent/783212/contributions/3512615/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512615/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Two-Loop QCD Helicity Amplitudes for Higgs Production Associated w
ith a Vector Boson through Bottom Quark Annihilation
DTSTART;VALUE=DATE-TIME:20190912T133000Z
DTEND;VALUE=DATE-TIME:20190912T135500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512618@indico.cern.ch
DESCRIPTION:Speakers: Taushif Ahmed (Max-Planck-Institut für Physik)\nPro
ductions of the Higgs boson in association with a massive vector boson\, i
.e. the VH events\, play an important role in the explorations of Higgs ph
ysics at the LHC\, both for a precise study of Higgs' Standard Model coupl
ings and for probing new physics. In this talk\, we present the 2-loop mas
sless QCD corrections to the helicity amplitudes of the associated Higgs p
roduction through the bottom quark-antiquark annihilation\, which is a nec
essary ingredient to the full NNLO QCD corrections to this process in the
5-flavor (PDF) schemes. The computation is performed by projecting the 2-l
oop amplitudes onto an appropriate set of Lorentz structures\, sufficient
for deriving all physical helicity amplitudes\, whose availability would l
ater allow us to combine the VH production with the subsequent decay of th
e massive vector boson with full spin correlations accounted. The axial co
ntributions are computed using Larin's prescription of the axial vertex (o
r gamma5)\, and the chiral Ward identities (or anomaly equations) of axial
currents are verified. We provide the analytic expressions of the finite
remainders of each helicity amplitudes in terms of polylogarithms of maxim
um weight four.\n\nhttps://indico.cern.ch/event/783212/contributions/35126
18/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512618/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Two loop QCD amplitudes for di-pseudoscalar Higgs production
DTSTART;VALUE=DATE-TIME:20190912T130000Z
DTEND;VALUE=DATE-TIME:20190912T132500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512575@indico.cern.ch
DESCRIPTION:Speakers: Prakash Mathews ()\nWe compute the two-loop massless
QCD corrections to the four point amplitude \ng + g -> A + A. Two operat
ors contribute this amplitude and the ultraviolet renormalisation requires
careful treatment involving mixing. The universal structure of the infra
red poles are studied in detail.\n\nhttps://indico.cern.ch/event/783212/co
ntributions/3512575/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512575/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On gg->ZZ production at two loops with full top mass dependence
DTSTART;VALUE=DATE-TIME:20190912T123000Z
DTEND;VALUE=DATE-TIME:20190912T125500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512573@indico.cern.ch
DESCRIPTION:Speakers: Bakul Agarwal (Michigan State University)\nIn this t
alk\, we discuss top quark contributions to ZZ production through gluon fu
sion at two loops. We use a syzygy based approach for the reductions to ma
ster integrals. In order to numerically evaluate the amplitude\, we expres
s it in terms of finite integrals\, which we construct out of linear combi
nations of divergent integrals using a new algorithm.\n\nhttps://indico.ce
rn.ch/event/783212/contributions/3512573/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512573/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The O(alpha^2) Initial State QED Corrections to e+ e- Annihilation
into a Neutral Vector Boson Revisited
DTSTART;VALUE=DATE-TIME:20190910T160000Z
DTEND;VALUE=DATE-TIME:20190910T162500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512555@indico.cern.ch
DESCRIPTION:Speakers: Kay Schönwald (DESY)\nAt $e^+ \\\, e^-$ colliders t
he QED--initial state radiation forms a large part of the radiative correc
tions. Their\nprecise and fast evaluation is an essential asset for the ex
periments at LEP\, the ILC and the FCC-ee\, operating at\nhigh luminosity.
A long standing problem in the analytic understanding of the $\\mathcal{O
}(\\alpha^2)$ initial state \nradiation is the observed discrepancy betwee
n the calculation of Berends et al. (1988) in the limit $m_e^2 \\ll s$ and
\nthe result of the effective calculation using massive operator matrix e
lements by Blümlein et al. (2011) aiming \ndirectly for this limit. In or
der to resolve this important issue we recalculated this process by integr
ating directly \nover the phase space without any approximation. For parts
of the corrections we find exact solutions of the cross section in \nterm
s of iterated \nintegrals over square root valued letters representing inc
omplete elliptic integrals and iterations over them.\nThe expansion in the
limit $m_e^2 \\ll s$ reveals errors in the constant $O(\\alpha^2)$ term o
f the former calculation \nand yields agreement with the calculation based
on massive operator matrix elements\, which has impact on the\nexperiment
al analysis programs. This finding also explicitly proofs the \nfactorizat
ion of massive initial state particles in the high energy limit at $\\math
cal{O}(\\alpha^2)$ for this process.\n\nhttps://indico.cern.ch/event/78321
2/contributions/3512555/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512555/
END:VEVENT
BEGIN:VEVENT
SUMMARY:QED challenges at FCC-ee precision measurements
DTSTART;VALUE=DATE-TIME:20190910T153000Z
DTEND;VALUE=DATE-TIME:20190910T155500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512542@indico.cern.ch
DESCRIPTION:Speakers: Jadach Stanislaw (IFJ PAN\, Kraków)\nThe expected e
xperimental precision of the rates and asymmetries\nin the Future Circular
Collider with electron positron beams (FCC-ee)\nin the energy range 88-36
5GeV considered for construction in CERN\,\nwill be better by a factor 5-2
00.\nThis will be thanks to very high luminosity\,\nfactor up to $10^5$ hi
gher than in the past LEP experiments.\nThis poses the extraordinary chall
enge of improving the precision\nof the Standard Model predictions by a co
mparable factor.\nIn particular the perturbative calculations of the trivi
al QED effects\,\nwhich have to be removed from the experimental data\,\na
re considered to be a major challenge for almost all\nquantities to be mea
sured at FCC-ee.\nThe task of this paper is to summarize on the ``state of
the art''\nin this class of the calculations left from the LEP era\nand t
o examine what is to be done\nto match the precision of the FCC-ee experim
ents --\nwhat kind of technical advancements are necessary.\nThe above ana
lysis will be done for most important observables\nof the FCC-ee like the
total cross sections near $Z$ and $WW$ threshold\,\ncharge asymmetries\,
the invisible width of $Z$ boson\, the spin asymmetry\nfrom tau lepton dec
ay and the luminosity measurement.\n\nhttps://indico.cern.ch/event/783212/
contributions/3512542/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512542/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Rational terms in two-loop calculations
DTSTART;VALUE=DATE-TIME:20190910T150000Z
DTEND;VALUE=DATE-TIME:20190910T152500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512593@indico.cern.ch
DESCRIPTION:Speakers: Max Zoller (UZH)\nRecently\, we published the OpenLo
ops 2 program\, a powerful tool for the automation of NLO QCD and NLO EW c
alculations for all relevant LHC processes with high numerical stability i
n hard regions as well as in soft and collinear regions. This not only all
ows for highly efficient and accurate NLO calculations\, but also for the
numerically stable computation of NNLO real-virtual contributions. \nIn th
is talk we present first steps towards the automation of the numerical cal
culation of two-loop amplitudes with four-dimensional numerators. The new
methods and results presented in this talk are expected to be published sh
ortly before the conference.\n\nhttps://indico.cern.ch/event/783212/contri
butions/3512593/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512593/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Threshold effects at next-to-leading power
DTSTART;VALUE=DATE-TIME:20190910T140000Z
DTEND;VALUE=DATE-TIME:20190910T142500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512585@indico.cern.ch
DESCRIPTION:Speakers: Jort Sinninghe Damsté (University of Amsterdam)\nIn
QCD\, soft radiation plays an important role in kinematic regions where r
esulting threshold logarithms become large. In this talk\, I address such
effects beyond leading power in the threshold expansion\, for both fixed o
rder and resummed results. For the double-real single-virtual correction t
o Drell-Yan\, a large class of next-to-leading power (NLP) threshold logar
ithms is shown\nto be obtained using the method of regions [1]. For more g
eneral processes with a colour singlet final state\, leading logarithms at
NLP are resummed by dressing the shifted Born level cross section with ex
ponentiated LP webs [2].\n\n\n[1] N. Bahjat-Abbas\, J. Sinninghe Damsté\,
L. Vernazza and C. D. White\, “On next-to-leading\npower threshold corr
ections in Drell-Yan production at N3LO”\, JHEP\n10 (2018) 144\, 1807.09
246.\n\n[2] N. Bahjat-Abbas\, D. Bonocore\, J. Sinninghe Damsté\, E. Laen
en\, L. Magnea\, L. Vernazza and\nC. D. White\, “Diagrammatic resummatio
n of leading-logarithmic threshold effects at next-to-leading\npower”\,
1905.13710.\n\nhttps://indico.cern.ch/event/783212/contributions/3512585/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512585/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The role of soft quarks in next-to-leading power threshold effects
DTSTART;VALUE=DATE-TIME:20190910T133000Z
DTEND;VALUE=DATE-TIME:20190910T135500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512628@indico.cern.ch
DESCRIPTION:Speakers: Melissa van Beekveld (R)\nCross-sections in perturba
tive QCD are plagued by large corrections from soft and collinear radiatio
n. The most singular terms are known to be universal\, which allows their
resummation to all orders in the coupling. In our work\, we have examined
the structure of the next-to-singular contributions\, which can originate
from the emission of both soft quarks and gluons. In this talk\, I will sh
ow that we can derive a next-to-soft amplitude for both types of emissions
. In addition\, I will show the numerical impact of these contributions on
the transverse momentum distribution of the single-photon production proc
ess.\n\nhttps://indico.cern.ch/event/783212/contributions/3512628/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512628/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Wilson-line geometries and the relation between IR singularities o
f form factors and the large-x limit of DGLAP splitting functions
DTSTART;VALUE=DATE-TIME:20190910T130000Z
DTEND;VALUE=DATE-TIME:20190910T132500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512572@indico.cern.ch
DESCRIPTION:Speakers: Calum Milloy (University of Edinburgh)\nWe discuss t
he relation between the infrared singularities of on-shell partonic form f
actors and parton distribution functions (PDFs) near the elastic limit\, t
hrough their factorisation in terms of Wilson-line correlators. Ultimately
we identify the difference between the anomalous dimension controlling si
ngle poles of these two quantities to all loops in terms of the closed par
allelogram Wilson loop. To arrive at this result we first use the common h
ard-collinear behaviour of the two to derive a relation between their resp
ective non-collinear soft singularities\, and then show that the latter is
manifested in terms of differing Wilson-line geometries. We use explicit
diagrammatic calculations in configuration space through two loops to veri
fy the relation. More generally\, the emerging picture allows us to classi
fy collinear singularities in eikonal quantities depending on whether they
are associated with finite (closed) Wilson-line segments or infinite (op
en) ones.\n\nhttps://indico.cern.ch/event/783212/contributions/3512572/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512572/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soft gluon resummation for the associated top-pair quark productio
n at the LHC
DTSTART;VALUE=DATE-TIME:20190910T123000Z
DTEND;VALUE=DATE-TIME:20190910T125500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512630@indico.cern.ch
DESCRIPTION:Speakers: Anna Kulesza ()\nThe studies of the associated produ
ction processes of a top-quark pair with a colour-singlet boson\, e.g. Hig
gs\, W or Z\, are among the highest priorities of the LHC programme. Corre
spondingly\, improvements in precision of theoretical predictions for thes
e processes are of central importance. In this talk\, we review the latest
results on resummation of soft gluon corrections. The resummation is carr
ied out using the direct QCD Mellin space technique in three-particle inva
riant mass kinematics. We discuss the impact of the soft gluon corrections
on the predictions for the total cross sections and the differential dist
ributions as well as compare the results with the recent measurements by A
TLAS and CMS.\n\nhttps://indico.cern.ch/event/783212/contributions/3512630
/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512630/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Charm mass dependent NNLO corrections to $\\mathcal{B}(\\bar{B} \\
rightarrow X_s \\gamma)$
DTSTART;VALUE=DATE-TIME:20190910T140000Z
DTEND;VALUE=DATE-TIME:20190910T142500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512543@indico.cern.ch
DESCRIPTION:Speakers: Abdur Rehman (KIT\, NCP (PK))\nThe inclusive radiati
ve decay of the B meson is known to provide strong constraints on new part
icles and their interactions. The current experimental world average for i
ts branching ratio is $(3.32 \\pm 0.15) \\cdot 10^{-4}$ which agrees withi
n one sigma with the present SM prediction $(3.36 \\pm 0.23) \\cdot 10^{-4
}$. Some of the NNLO QCD corrections are included with the help of interpo
lation in the charm quark mass\, which causes about 3 percent uncertainty
in present SM prediction. Efforts towards removing this uncertainty is the
topic of talk. We will present charm quark mass dependent contributions t
hat require evaluation of two scales four-loop propagator diagrams with un
itarity cuts.\n\nhttps://indico.cern.ch/event/783212/contributions/3512543
/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512543/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Precision measurements at the LHC
DTSTART;VALUE=DATE-TIME:20190909T071500Z
DTEND;VALUE=DATE-TIME:20190909T080000Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3548182@indico.cern.ch
DESCRIPTION:Speakers: Simone Amoroso (Deutsches Elektronen-Synchrotron (DE
))\nThis talk reviews experimental results of the ATLAS and CMS collaborat
ions at the LHC\, comprising SM\, Top and Higgs measurements\n\nhttps://in
dico.cern.ch/event/783212/contributions/3548182/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3548182/
END:VEVENT
BEGIN:VEVENT
SUMMARY:International Advisory Board meeting
DTSTART;VALUE=DATE-TIME:20190912T163000Z
DTEND;VALUE=DATE-TIME:20190912T180000Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3547332@indico.cern.ch
DESCRIPTION:https://indico.cern.ch/event/783212/contributions/3547332/
LOCATION: Petite Cuisine
URL:https://indico.cern.ch/event/783212/contributions/3547332/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The two-loop five-gluon all-plus helicity amplitude
DTSTART;VALUE=DATE-TIME:20190909T160000Z
DTEND;VALUE=DATE-TIME:20190909T162500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3547322@indico.cern.ch
DESCRIPTION:Speakers: Dmitry Chicherin (Max Planck Institute for Physics)\
nAs the experimental precision at the LHC keeps improving\, \nnext-to-next
-to leading order (NNLO) corrections for scattering processes have become
crucial for providing theoretical predictions of comparable accuracy. At p
resent\, only observables involving up to four particles are available at
this order. The main bottleneck towards higher multiplicity observables is
the analytic calculation of the required two-loop scattering amplitudes.
I present the first fully analytic result for a full-color two-loop five-p
article amplitude: the \nfive-gluon amplitude in the all-plus helicity con
figuration. In order to achieve it\, we analytically calculated all master
integrals that describe the NNLO virtual corrections for the three-jet pr
oduction. We express the amplitude in a remarkably compact form containing
only logarithms\, dilogarithms\, and rational functions.\n\nhttps://indic
o.cern.ch/event/783212/contributions/3547322/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3547322/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The four-loop slope of the Dirac form factor
DTSTART;VALUE=DATE-TIME:20190913T103000Z
DTEND;VALUE=DATE-TIME:20190913T105500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3546752@indico.cern.ch
DESCRIPTION:Speakers: Stefano Laporta (University of Padova)\nI this talk
I will show the result of the 1100-digits calculation of the 4-loop QED
contribution to the first derivative of the Dirac form factor at zero mome
ntum transfer. An analytical fit has been obtained\, and I will describe i
ts structure. I will discuss also the contribution of this result to the L
amb shift of hydrogen.\n\nhttps://indico.cern.ch/event/783212/contribution
s/3546752/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3546752/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Elastic neutrino-electron scattering within the effective field th
eory approach
DTSTART;VALUE=DATE-TIME:20190911T103000Z
DTEND;VALUE=DATE-TIME:20190911T105500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3519056@indico.cern.ch
DESCRIPTION:Speakers: Oleksandr Tomalak (University of Kentucky)\nElastic
neutrino-electron scattering provides an important tool for normalizing ne
utrino flux in modern experiments. This process is subject to large radiat
ive corrections. We determine the Fermi effective theory performing the on
e-loop matching to the Standard model at the electroweak scale with subseq
uent running down to GeV scale. Based on this theory\, we analytically eva
luate virtual corrections and distributions with one radiated photon beyon
d the electron energy spectrum. We discuss the relevance of radiative corr
ections depending on conditions of modern and future accelerator-based neu
trino experiments.\n\nhttps://indico.cern.ch/event/783212/contributions/35
19056/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3519056/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quark condensate and spectral density from renormalization group o
ptimized perturbation
DTSTART;VALUE=DATE-TIME:20190912T153000Z
DTEND;VALUE=DATE-TIME:20190912T155500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512591@indico.cern.ch
DESCRIPTION:Speakers: Jean-Loic Kneur (Univ. Montpellier)\nOur renormaliza
tion group consistent version of optimized perturbation\, RGOPT\, had been
used to calculate the nonperturbative QCD spectral density of the Dirac o
perator and the related chiral quark condensate $\\langle \\bar q q \\rang
le$\, for $n_f=2$ and $n_f=3$ massless quarks. Sequences of approximations
at two-\, three-\, and four-loop orders gave stable parameter-free determ
inations \n$\\langle\\bar q q\\rangle^{1/3}_{n_f=2}(2\\\, {\\rm GeV}) = -(
0.833-0.845) \\bar\\Lambda_2 $\, and $ \\langle\\bar q q\\rangle^{1/3}_{n_
f=3}(2\\\, {\\rm GeV}) = -(0.814-0.838) \\bar\\Lambda_3 $\, where the ran
ge is our estimated theoretical error and $\\bar\\Lambda_{n_f}$ the basic
QCD scale in the $\\overline{MS}$-scheme. \nWe update our previous analysi
s up to 5-loop order of (RG optimized) perturbation\, thanks to the recent
ly available five-loop order QCD renormalization group functions\, and com
pare our results with other recent determinations from lattice simulations
or other approaches.\n\nhttps://indico.cern.ch/event/783212/contributions
/3512591/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512591/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Photon pair production in gluon fusion: Top quark threshold effect
s
DTSTART;VALUE=DATE-TIME:20190913T100000Z
DTEND;VALUE=DATE-TIME:20190913T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512583@indico.cern.ch
DESCRIPTION:Speakers: Long Chen (Max Planck Institute for Physics)\nWe pre
sent a calculation of the NLO QCD corrections to the loop-induced producti
on of a photon pair through gluon fusion\, including massive top quarks at
two loops\, where the two-loop integrals are calculated numerically. Matc
hing the results for the virtual amplitude to a threshold expansion\, we o
btain accurate results around the top quark pair production threshold. We
analyse how the top quark threshold corrections affect distributions of th
e photon pair invariant mass and comment on the possibility to determine t
he top quark mass from precision measurements of the diphoton invariant ma
ss spectrum.\n\nhttps://indico.cern.ch/event/783212/contributions/3512583/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512583/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Higher order corrections to Higgs boson pair production
DTSTART;VALUE=DATE-TIME:20190913T073000Z
DTEND;VALUE=DATE-TIME:20190913T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512531@indico.cern.ch
DESCRIPTION:Speakers: Matthias Steinhauser (KIT)\nIn this talk we discuss
NNLO and N3LO order corrections\nto the process gg->HH in the Standard Mod
el. In particular\,\nwe consider three-loop corrections to the form factor
s entering the virtual\ncorrections in the large-mt\nlimit and compute fiv
e expansion terms.\nIn the same approximation we also evaluate the\nreal r
adiation corrections at NNLO. Finally\, we present\na building block for t
he N3LO corrections\, namely the\nfour-loop matching coefficient for the e
ffective coupling\nof two Higgs bosons to gluons.\n\nhttps://indico.cern.c
h/event/783212/contributions/3512531/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512531/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Non-factorizable QCD Effects in Higgs Boson Production via Vector
Boson Fusion
DTSTART;VALUE=DATE-TIME:20190909T140000Z
DTEND;VALUE=DATE-TIME:20190909T142500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512548@indico.cern.ch
DESCRIPTION:Speakers: Alexander Penin (University of Alberta)\nWe discuss
nonfactorizable QCD corrections to Higgs boson production in vector boson
fusion at the Large Hadron Collider. We point out that these corrections c
an be computed in the eikonal approximation retaining all the terms that a
re not suppressed by the ratio of the transverse momenta of the tagging je
ts to the total center-of-mass energy. Our analysis shows that in certain
kinematic distributions the nonfactorizable corrections can be as large as
a percent making them quite comparable to their factorizable counter-part
s.\n\nhttps://indico.cern.ch/event/783212/contributions/3512548/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512548/
END:VEVENT
BEGIN:VEVENT
SUMMARY:N3LO predictions for the decay of the Higgs boson to bottom quarks
DTSTART;VALUE=DATE-TIME:20190913T093000Z
DTEND;VALUE=DATE-TIME:20190913T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512584@indico.cern.ch
DESCRIPTION:Speakers: Roberto Mondini (University at Buffalo)\nWe present
a fully-differential calculation of the $H \\to b\\overline{b}$ decay at n
ext-to-next-to-next-to-leading order (N3LO) accuracy. Our calculation con
siders diagrams in which the Higgs boson couples directly to the bottom qu
arks. In order to regulate the infrared divergences present at this order
we use the Projection-to-Born technique coupled with N-jettiness slicing.
After validating our methodology at next-to-next-to-leading order (NNLO) w
e present exclusive jet rates and differential distributions for jet obser
vables at N3LO accuracy using the Durham jet algorithm in the Higgs rest f
rame.\n\nhttps://indico.cern.ch/event/783212/contributions/3512584/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512584/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Binary Black Holes and Scattering Amplitudes
DTSTART;VALUE=DATE-TIME:20190913T090000Z
DTEND;VALUE=DATE-TIME:20190913T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512556@indico.cern.ch
DESCRIPTION:Speakers: Mikhail Solon ()\nWe combine tools from the modern a
mplitudes program and effective field theory to develop a systematic and s
calable method for deriving classical dynamics for binary systems from on-
shell scattering. Applying this to gravitationally interacting massive sca
lars yields the first derivation of the conservative Hamiltonian for compa
ct spinless binaries at third post-Minkowskian order. The resulting Hamilt
onian is in complete agreement with corresponding terms in state-of-the-ar
t expressions at fourth post-Newtonian order as well as the probe limit at
all orders in velocity. Prospects for improving the accuracy of theoretic
al waveform templates employed in gravitational wave detection are discuss
ed.\n\nhttps://indico.cern.ch/event/783212/contributions/3512556/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512556/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Matter dependence of the four-loop cusp anomalous dimension
DTSTART;VALUE=DATE-TIME:20190913T080000Z
DTEND;VALUE=DATE-TIME:20190913T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512570@indico.cern.ch
DESCRIPTION:Speakers: Maximilian Stahlhofen (JGU Mainz)\nThe cusp anomalou
s dimension is a universal and ubiquitous quantity in QCD. It governs the
IR structure of scattering amplitudes and is the key ingredient to (Sudako
v) resummation for high-energy collider processes. I will report on recent
analytic results on the matter dependence of the cusp anomalous dimension
at four loops and discuss the calculational methods used to obtain them.\
n\nhttps://indico.cern.ch/event/783212/contributions/3512570/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512570/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Generalized hypergeometric functions and intersection theory for F
eynman integrals
DTSTART;VALUE=DATE-TIME:20190913T070000Z
DTEND;VALUE=DATE-TIME:20190913T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512629@indico.cern.ch
DESCRIPTION:Speakers: Ruth Britto (Trinity College Dublin)\nFeynman integr
als that have been evaluated in dimensional regularization can be written
in terms of generalized hypergeometric functions. It is well known that pr
operties of these functions are revealed in the framework of intersection
theory. We propose further applications of intersection theory in the case
of functions associated to positive geometries\, in particular to constru
ct a mathematical coaction\, which has played an important role in recent
progress in physical calculations.\n\nhttps://indico.cern.ch/event/783212/
contributions/3512629/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512629/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Role of IR-improvement in Precision LHC/FCC Physics and in Quantum
Gravity
DTSTART;VALUE=DATE-TIME:20190912T160000Z
DTEND;VALUE=DATE-TIME:20190912T162500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3520687@indico.cern.ch
DESCRIPTION:Speakers: Bennie Ward (Baylor University (US))\nIR-improvement
based on amplitude-level resummation allows one to control unintegrable r
esults in quantum field theory with arbitrary precision in principle. We i
llustrate such resummation in specific examples in precision LHC and FCC p
hysics and in quantum gravity.\n\nhttps://indico.cern.ch/event/783212/cont
ributions/3520687/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3520687/
END:VEVENT
BEGIN:VEVENT
SUMMARY:ISR and IFI in Precision AFB Studies with KKMC-hh
DTSTART;VALUE=DATE-TIME:20190912T153000Z
DTEND;VALUE=DATE-TIME:20190912T155500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3520688@indico.cern.ch
DESCRIPTION:Speakers: Scott Alan Yost (The Citadel - The Military College
of South Carolina (US))\, Scott Yost (The Citadel)\nKKMC-hh is a precisio
n event generator for Z boson production at a hadron collider\, based on c
oherent exclusive exponentiation (CEEX) of soft photon emission at the amp
litude level. We will summarize studies of ISR and IFI effects on calculat
ions AFB for precision EW analysis at the LHC. Different approaches to IS
R will be compared\, and progress will be reported on implementing NLO QCD
in KKMC-hh.\n\nhttps://indico.cern.ch/event/783212/contributions/3520688/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3520688/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Off-shell renormalization of spontaneously broken effective gauge
theories
DTSTART;VALUE=DATE-TIME:20190912T150000Z
DTEND;VALUE=DATE-TIME:20190912T152500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3519060@indico.cern.ch
DESCRIPTION:Speakers: Andrea Quadri (INFN\, Sez. di Milano)\nThe consisten
t recursive subtraction of UV divergences order by order in the loop expan
sion for spontaneously broken effective gauge theories with higher dimensi
on derivative operators is presented. The Slavnov-Taylor identity is solve
d to all orders in the loop expansion by homotopy techniques and a suitabl
e choice of invariant field coordinates (named bleached variables) for the
linearly realized gauge group. This allows one to disentangle the gauge-i
nvariant contributions to off-shell 1-PI amplitudes from those associated
with the gauge-fixing and (generalized) non-polynomial field redefinitions
(that do appear already at one loop). Explicit examples for dimension-6 o
perators are presented.\n\nhttps://indico.cern.ch/event/783212/contributio
ns/3519060/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3519060/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Polarized and unpolarized heavy flavor corrections to DIS in 2- a
nd 3-loop order-loop
DTSTART;VALUE=DATE-TIME:20190912T150000Z
DTEND;VALUE=DATE-TIME:20190912T152500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512550@indico.cern.ch
DESCRIPTION:Speakers: Johannes Bluemlein (DESY)\nRecent results are presen
ted on polarized and unpolarized heavy flavor corrections\nto DIS to 2- an
d 3-loop order in the full region and for large virtualities. \nIn the pol
arized case we also discuss the treatment of \\gamma_5 and derive \nresult
s in the M-scheme.\n\nhttps://indico.cern.ch/event/783212/contributions/35
12550/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512550/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heavy meson hadroproduction:open issues
DTSTART;VALUE=DATE-TIME:20190912T160000Z
DTEND;VALUE=DATE-TIME:20190912T162500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3519055@indico.cern.ch
DESCRIPTION:Speakers: Maria Vittoria Garzelli (Universita e INFN\, Firenze
(IT))\nIn this talk I will present open issues in the deacription of proc
esses leading to the hadroproduction of at least one heavy meson or baryon
\, considering different flavour number schemes. Solving these issues is
important for improving the accuracy of PDf fits and of predictions in hig
h-energy astroparticle physics.\n\nhttps://indico.cern.ch/event/783212/con
tributions/3519055/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3519055/
END:VEVENT
BEGIN:VEVENT
SUMMARY:CP even and odd Higgs boson production in electron-photon collisio
ns
DTSTART;VALUE=DATE-TIME:20190912T100000Z
DTEND;VALUE=DATE-TIME:20190912T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3519058@indico.cern.ch
DESCRIPTION:Speakers: Tsuneo Uematsu (Kyoto University)\nWithin the frame
work of the standard model as well as the two Higgs\ndoublet model includi
ng the MSSM as a special case\, we examine the\nCP-even and CP-odd Higgs b
oson production in electron-photon collisions.\nWe particularly emphasize
the role of the transition form factor\nin terms of which the production a
mplitudes can be given.\n\nhttps://indico.cern.ch/event/783212/contributio
ns/3519058/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3519058/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Cross section ratios as a precision tool for ttgamma at the LHC
DTSTART;VALUE=DATE-TIME:20190912T093000Z
DTEND;VALUE=DATE-TIME:20190912T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512530@indico.cern.ch
DESCRIPTION:Speakers: Malgorzata Worek (RWTH Aachen University )\nWith the
goal of increasing the precision of NLO QCD predictions for the pp->ttγ
process in the di-lepton top quark decay channel we present theoretical pr
edictions for the cross section ratio. Results for the latter together wit
h various differential cross section ratios will be presented for the LHC
Run II energy of 13 TeV. Fully realistic NLO QCD computations for both tt
and ttγ production will be discussed as well.\n\nhttps://indico.cern.ch/e
vent/783212/contributions/3512530/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512530/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Top-quark effects in diphoton production through gluon fusion at N
LO in QCD
DTSTART;VALUE=DATE-TIME:20190912T090000Z
DTEND;VALUE=DATE-TIME:20190912T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512602@indico.cern.ch
DESCRIPTION:Speakers: Xiaoran Zhao ()\nAt hadron colliders\, the leading p
roduction mechanism for a pair of photons is from quark-anti-quark annihil
ation at the tree level. However\, due to large gluon-gluon luminosity\, t
he loop-induced process $gg\\to \\gamma \\gamma$ provides a substantial co
ntribution. In particular\, the amplitudes mediated by the top quark becom
e important at the $t \\bar t$ threshold and above. In this letter we pres
ent the first complete computation of the next-to-leading order (NLO) corr
ections (up to $\\alpha_S^3$) to this process\, including contributions fr
om the top quark. These entail two-loop diagrams with massive propagators
whose analytic expressions are unknown and have been evaluated numerically
. We find that the NLO corrections to the top-quark induced terms are very
large at low diphoton invariant mass $m(\\gamma \\gamma)$ and close to th
e $t \\bar t$ threshold. The full result including five massless quarks an
d top quark contributions at NLO displays a much more pronounced change of
slope in the $m(\\gamma \\gamma)$ distribution at $t \\bar t$ threshold t
han at LO and an enhancement at high invariant mass with respect to the ma
ssless calculation.\n\nhttps://indico.cern.ch/event/783212/contributions/3
512602/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512602/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Systematic integration of higher loop gauge theory amplitudes in p
osition space
DTSTART;VALUE=DATE-TIME:20190912T100000Z
DTEND;VALUE=DATE-TIME:20190912T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512603@indico.cern.ch
DESCRIPTION:Speakers: Michael Borinsky (Nikhef)\nRecently\, there have bee
n remarkable advances concerning the systematic integration of higher loop
Feynman amplitudes. A synthesis of differential equation and number theor
etical methods can be employed to calculate position space Feynman amplitu
des in the massless case. The combination of these two methods makes this
approach very efficient\, as an IBP reduction step can be bypassed. We wil
l review on how these techniques were used by one of the authors to calcul
ate the 7-loop beta function in phi^4 theory in D=4. Moreover\, we will sh
ow how these methods can be extended to general even dimensions and illust
rate a further extension to gauge theories.\n\nhttps://indico.cern.ch/even
t/783212/contributions/3512603/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512603/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Padé approach to top-quark mass effects in gluon fusion amplitude
s
DTSTART;VALUE=DATE-TIME:20190912T093000Z
DTEND;VALUE=DATE-TIME:20190912T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512588@indico.cern.ch
DESCRIPTION:Speakers: Thomas Johannes Georg Rauh (Universität Bern)\nGluo
n fusion processes like single and double Higgs production exhibit slow co
nvergence and pose severe computational challenges. We show how the top-qu
ark mass dependence of the virtual amplitudes can be reconstructed with a
conformal mapping and Padé approximants based on the expansion in the inv
erse top-quark mass and the non-analytic terms in the expansion around the
top threshold. The method is then applied at two- and three-loop order.\n
\nhttps://indico.cern.ch/event/783212/contributions/3512588/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512588/
END:VEVENT
BEGIN:VEVENT
SUMMARY:A refined machinery to calculate large moments from coupled system
s of linear differential equations
DTSTART;VALUE=DATE-TIME:20190912T090000Z
DTEND;VALUE=DATE-TIME:20190912T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512552@indico.cern.ch
DESCRIPTION:Speakers: Carsten Schneider (RISC\, Johannes Kepler University
Linz)\nRecently\, we have worked out how thousands of moments of Feynman
integrals can be computed if they are represented by coupled systems of li
near differential equations and sufficiently many initial values. Given th
ese moments one is in the position to derive recurrence relations and to s
olve these recurrences\, e.g.\, within the class of indefinite nested sums
. In this talk we will present a refined version of this large moment meth
od that speeds up the necessary calculation steps and that reduces the num
ber of needed initial values. We show that this improved machinery can be
used efficiently to calculate\, e.g.\, contributions of the 3-loop massive
form factor.\n\nhttps://indico.cern.ch/event/783212/contributions/3512552
/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512552/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Next-to-leading power factorization in threshold DY production
DTSTART;VALUE=DATE-TIME:20190912T080000Z
DTEND;VALUE=DATE-TIME:20190912T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512594@indico.cern.ch
DESCRIPTION:Speakers: Sebastian Jaskiewicz (Technical University of Munich
)\nSoft Collinear Effective Theory (SCET) formalism has been successfully
applied to a number of important observables in collider physics improving
the accuracy of fixed-order predictions via the leading power resummation
of large logarithmic contributions which appear in certain regions of pha
se space. Recently\, a renewed interest in subleading power corrections ha
s arisen in the theoretical community. In this talk\, I will discuss the f
ramework for the threshold resummation of the Drell-Yan process and Higgs
production via gluon fusion at next-to-leading power using SCET. I will pr
ove the general factorisation formula and explain the new objects that eme
rge beyond leading power: collinear jet functions and generalized soft fun
ctions. The ingredients necessary to perform leading logarithmic resummati
on at next-to-leading power will be shown and I will present selected fix
ed order results.\n\nhttps://indico.cern.ch/event/783212/contributions/351
2594/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512594/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Factorisation and resummation for double differential cross-sectio
n in tau_1 and tau_0
DTSTART;VALUE=DATE-TIME:20190912T073000Z
DTEND;VALUE=DATE-TIME:20190912T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512619@indico.cern.ch
DESCRIPTION:Speakers: Goutam Das (DESY)\nWe present a factorisation formul
a for the double differential cross-section in the N-jettiness variables
τ1 and τ0. The phase space spanned by these two variables are already kn
own in different hierarchies between them. However the region τ1 ~ τ0 is
not well known due to absence of a proper factorisation formula in this s
cenario. This region corresponds to two unordered but resolved emissions.
We present the factorisation formula first time for such unordered emissio
ns. We use Soft collinear Effective theory (SCET) to separate the soft and
collinear modes contribution at the measurement level. Using the power co
unting argument in SCET\, we completely separate the collinear and soft co
ntribution which are encoded inside Beam and Soft functions respectively.
We also comment on the structure of these objects as well as on their cons
istencies. Finally we describe the resummation and matching with other reg
ions of phase space in particular the SCET+ region with strongly ordered e
missions. This has immediate application on the improvement of parton show
er accuracy in Geneva framework at NNLL' accuracy as well as on the jet s
ubstructure observables without hierarchies.\n\nhttps://indico.cern.ch/eve
nt/783212/contributions/3512619/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512619/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Evolution equation for B-meson distribution amplitude at two loops
DTSTART;VALUE=DATE-TIME:20190912T070000Z
DTEND;VALUE=DATE-TIME:20190912T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512544@indico.cern.ch
DESCRIPTION:Speakers: Alexander Manashov (Hamburg University)\nThe B-meson
distribution amplitude is defined by the matrix element of a heavy-light
quark operator between the vacuum and B-meson states. The scale dependenc
e of the corresponding DA is governed by the renormalization group equatio
n for this operator. At one loop the corresponding evolution kernel was de
rived by Lange and Neubert. I'll argue that the form of the kernel is stro
ngly restricted by the conformal symmetry and present the answer for the t
wo-loop kernel.\n\nhttps://indico.cern.ch/event/783212/contributions/35125
44/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512544/
END:VEVENT
BEGIN:VEVENT
SUMMARY:From sum-integrals to continuum integrals and back
DTSTART;VALUE=DATE-TIME:20190912T080000Z
DTEND;VALUE=DATE-TIME:20190912T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512582@indico.cern.ch
DESCRIPTION:Speakers: York Schröder (UBB Chillán)\nWithin finite-tempera
ture quantum field theory\, the evaluation of vacuum-type sum-integrals pl
ays a central role in the determination of equilibrium observables\, such
as the free energy (or pressure) of a thermal system.\n\nAs has been repea
tedly observed in the past\, many two-loop sum-integrals can be decomposed
into one-loop factors\, allowing for analytic solutions in the space-time
dimension $d$.\n\nIn this talk\, we sketch a recent proof that this decom
position is generic\, and give an algorithm that constructs this decomposi
tion for any massless bosonic two-loop vacuum sum-integral. A number of re
lated insights into a special class of two-loop massive vacuum integrals a
re discussed along the way.\n\nhttps://indico.cern.ch/event/783212/contrib
utions/3512582/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512582/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Planar Master Integrals for the two-loop light-fermions electrowea
k corrections to Higgs plus jet production
DTSTART;VALUE=DATE-TIME:20190912T073000Z
DTEND;VALUE=DATE-TIME:20190912T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512576@indico.cern.ch
DESCRIPTION:Speakers: Valerio Casconi (Università La Sapienza)\nIn this t
alk\, I will present the analytic calculation of the planar master integra
ls for the two-loop light-fermion electroweak corrections for the producti
on of a Higgs boson in the gluon-gluon fusion channel. The complete depend
ence on the electroweak boson mass is retained. The master integrals are e
valuated by means of the differential equations method and the analytic re
sult are expressed in terms of multiple polylogarithms up to weight four.\
nThe Higgs signals provide a strong test of the Standard Model and can be
a probe of New Physics in case a deviation from the SM behavior of the Hig
gs properties will be revealed.\n\nhttps://indico.cern.ch/event/783212/con
tributions/3512576/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512576/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Master Integrals for the two-loop\, non-planar QCD corrections to
top-quark pair production in the quark-annihilation channel
DTSTART;VALUE=DATE-TIME:20190912T070000Z
DTEND;VALUE=DATE-TIME:20190912T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512574@indico.cern.ch
DESCRIPTION:Speakers: Matteo Becchetti (Center for Cosmology\, Particle Ph
ysics and Phenomenology (CP3)\, Univeritè Catholique de Louvain )\nWe pre
sent the analytic calculation of the Master Integrals for certain two-loop
\, non-planar topologies that enter the calculation of the amplitude for t
op-quark pair hadroproduction in the quark-annihilation channel. These Mas
ter Integrals are needed to complete the evaluation of the two color facto
rs in the quark-annihilation channel which are not yet known analytically
at two-loop. We compute the Master Integrals using the method of different
ial equations in canonical form. The solution is given as a series expansi
on in the dimensional regularisation parameter through to weight four\, th
e expansion coefficients are given in terms of generalized harmonic polylo
garithms of two dimensionless variables.\n\nhttps://indico.cern.ch/event/7
83212/contributions/3512574/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512574/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Top mass effects in HJ and HH production
DTSTART;VALUE=DATE-TIME:20190911T103000Z
DTEND;VALUE=DATE-TIME:20190911T105500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512624@indico.cern.ch
DESCRIPTION:Speakers: Matthias Kerner (University of Zürich)\nI will pres
ent NLO corrections to Higgs boson production in association with a jet\,
retaining the full dependence on the top quark mass. Details of the calcul
ation will be presented\, focusing on the evaluation of the two-loop integ
rals\, which is done numerically with the program SedDec. In particular I
will present various improvements to the code\, which have been achieved s
ince the first publication of the results\, resulting in an improved stabi
lity and reduced run time of the program.\n\nhttps://indico.cern.ch/event/
783212/contributions/3512624/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512624/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On the four-loop form factors of massless QCD
DTSTART;VALUE=DATE-TIME:20190911T100000Z
DTEND;VALUE=DATE-TIME:20190911T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512547@indico.cern.ch
DESCRIPTION:Speakers: Robert Schabinger ()\nIn this talk\, we discuss our
ongoing calculation of the four-loop form factors of massless QCD. In part
icular\, we present results for the quark and gluon form factors which we
have calculated for the first time using novel computational techniques.\n
\nhttps://indico.cern.ch/event/783212/contributions/3512547/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512547/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Heavy quark form factors at three loops
DTSTART;VALUE=DATE-TIME:20190911T093000Z
DTEND;VALUE=DATE-TIME:20190911T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512549@indico.cern.ch
DESCRIPTION:Speakers: Peter Marquard (DESY)\nWe present new results for he
avy quark form factors at three loop order.\n\nhttps://indico.cern.ch/even
t/783212/contributions/3512549/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512549/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Four-Loop Higgs- and Z-Decay and the Five-Loop Beta-Function
DTSTART;VALUE=DATE-TIME:20190911T090000Z
DTEND;VALUE=DATE-TIME:20190911T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3519059@indico.cern.ch
DESCRIPTION:Speakers: Johann Kuehn ()\nRecent results concerning Higgs- an
d Z-boson decay rate\nin order alpha**4 and the five-loop beta-function ar
e presented.\n\nhttps://indico.cern.ch/event/783212/contributions/3519059/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3519059/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The Gravitational Potential of Two Point Masses at Five Loops
DTSTART;VALUE=DATE-TIME:20190911T100000Z
DTEND;VALUE=DATE-TIME:20190911T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512581@indico.cern.ch
DESCRIPTION:Speakers: Andreas Maier (DESY)\nHigher-order corrections to th
e interaction potential between non-relativistic massive objects can be ob
tained systematically in a Post-Newtonian expansion in the small velocity
and weak coupling. We present the calculation of these corrections up to f
ive loops using techniques from multi-loop computations in high-energy phy
sics.\n\nhttps://indico.cern.ch/event/783212/contributions/3512581/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512581/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Orbital dynamics from the double copy and effective field theory
DTSTART;VALUE=DATE-TIME:20190911T093000Z
DTEND;VALUE=DATE-TIME:20190911T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512579@indico.cern.ch
DESCRIPTION:Speakers: Mao Zeng (UC Los Angeles)\nWe compute the third-post
-Minkowskian conservative Hamiltonian of binary black holes using modern t
ools from scattering amplitudes and effective field theory. In the limit o
f large separation\, non-spinning black holes have an effective descriptio
n in terms scalar field particles coupled to gravity. The two-loop integra
nd is constructed using generalized unitarity and the double copy construc
tion. We perform loop integration by expanding around zero velocity to hig
h orders\, using techniques borrowed from NRQCD\, before matching the seri
es to known functions. For some diagrams\, we also validate the results us
ing the method of differential equations. We comment on spurious collinear
singularities that arise from the truncation of the quantum amplitude to
the classical limit.\n\nhttps://indico.cern.ch/event/783212/contributions/
3512579/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512579/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Calculating the static gravitational two-body potential to fifth p
ost-Newtonian order with Feynman diagrams
DTSTART;VALUE=DATE-TIME:20190911T090000Z
DTEND;VALUE=DATE-TIME:20190911T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512600@indico.cern.ch
DESCRIPTION:Speakers: Christian Sturm ()\nThe effective field theory appro
ach to general relativity allows to\napply techniques for computing Feynma
n diagrams used in high energy\nphysics in order to calculate the gravitat
ional two-body potential. In the\ntalk I will discuss the first-time calcu
lation of the static two-body\npotential to fifth post-Newtonian order. Th
ese results were achieved\nthanks to a manifest factorization property of
Feynman diagrams. The\ntalk is based on arXiv:1902.10571.\n\nhttps://indic
o.cern.ch/event/783212/contributions/3512600/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512600/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Violation of the Kluberg-Stern-Zuber theorem and operator mixing i
n SCET
DTSTART;VALUE=DATE-TIME:20190911T073000Z
DTEND;VALUE=DATE-TIME:20190911T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512596@indico.cern.ch
DESCRIPTION:Speakers: Martin Beneke (Technische Universitaet Muenchen (DE)
)\nA well-known result states that operators that vanish by the classical
equation of motion do not mix into physical operators. The result guarante
es that the S-matrix is invariant under large classes of field redefinitio
ns. It is shown that (and why) the theorem is violated in soft-collinear e
ffective theory beyond the leading power in the soft-collinear expansion.
The mixing of eom operators into physical operators is computed at next-to
-leading power (NLP)\, which completes the one-loop renomalization of NLP
N-jet operators. It is explained how to deal with divergent collinear con
volution integrals.\n\nhttps://indico.cern.ch/event/783212/contributions/3
512596/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512596/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Threshold resummation at next-to-leading power
DTSTART;VALUE=DATE-TIME:20190911T080000Z
DTEND;VALUE=DATE-TIME:20190911T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512580@indico.cern.ch
DESCRIPTION:Speakers: Robert Szafron (TU München)\nIn this talk\, I am go
ing to report on the resummation of the leading logarithmic corrections fo
r the Drell-Yan production and Higgs production in gluon fusion at the nex
t-to-leading power in threshold expansion. I will describe how the kinema
tic power-corrections are accounted for and the structure of renormalisati
on group equations for the generalised soft function which appears after f
actorisation of the time-ordered products. These include power-suppressed
terms in the SCET Lagrangian. The leading logarithmic solution of the RG e
quations will be presented\, I will perform a comparison with known fixed
order results\, and comment on the impact for phenomenological studies.\n\
nhttps://indico.cern.ch/event/783212/contributions/3512580/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512580/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Master integrals for all unitarity cuts of massless 4-loop propaga
tors
DTSTART;VALUE=DATE-TIME:20190911T070000Z
DTEND;VALUE=DATE-TIME:20190911T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512532@indico.cern.ch
DESCRIPTION:Speakers: Vitalii Maheria ()\nAmong the unitarity cuts of mass
less 4-loop propagators two classes remain unknown: 2-loop 3-particle\, an
d 1-loop 4-particle cuts. I'd like to fill this gap and present the calcul
ation of master integrals for both of these cuts. I would also like to dis
cuss the ongoing work of using those to compute semi-inclusive phase-space
integrals relevant to the calculation of NNLO time-like splitting functio
ns.\n\nhttps://indico.cern.ch/event/783212/contributions/3512532/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512532/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Intersection Theory and Higgs Physics
DTSTART;VALUE=DATE-TIME:20190911T080000Z
DTEND;VALUE=DATE-TIME:20190911T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512590@indico.cern.ch
DESCRIPTION:Speakers: Hjalte Axel Frellesvig (University of Padova)\nWhen
finding linear relations between Feynman integrals using integration-by-pa
rts identities\, a very large linear system has to be solved as an interme
diate step.\nThis makes other approaches to the derivation of these identi
ties a worthwhile pursuit. In this context\, the concept of the intersecti
on number is of interest\, as it allows for the definition of (what amount
s to) a scalar product between Feynman integrals\, allowing the coefficien
ts of the master integrals to be extracted using ordinary projections in t
he space of Feynman integrals. \nUsing this novel method\, we will derive
and discuss a number of identities between Feynman integrals relevant for
Higgs physics.\n\nhttps://indico.cern.ch/event/783212/contributions/35125
90/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512590/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Diagrammatic Coaction of Two-Loop Feynman Integrals
DTSTART;VALUE=DATE-TIME:20190911T073000Z
DTEND;VALUE=DATE-TIME:20190911T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512587@indico.cern.ch
DESCRIPTION:Speakers: James Matthew (University of Edinburgh)\nIt is known
that one-loop Feynman integrals possess an algebraic structure encoding t
heir analytic properties called the coaction\, which can be written in ter
ms of Feynman integrals and their cuts. This diagrammatic coaction\, and t
he coaction on other classes of integrals such as hypergeometric functions
\, may be expressed using suitable bases of differential forms and integra
tion contours. This provides a useful framework for computing coactions of
Feynman integrals expressed using the hypergeometric functions. We will d
iscuss recent developments in the calculation of two-loop diagrammatic coa
ctions using this technique.\n\nhttps://indico.cern.ch/event/783212/contri
butions/3512587/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512587/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Decomposition of Feynman Integrals on the Maximal Cut by Intersect
ion Numbers
DTSTART;VALUE=DATE-TIME:20190911T070000Z
DTEND;VALUE=DATE-TIME:20190911T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512620@indico.cern.ch
DESCRIPTION:Speakers: Manoj Kumar Mandal ()\nThe reduction of a large numb
er of scalar multi-loop integrals to the smaller set of Master Integrals i
s an integral part of the computation of any multi-loop amplitudes. The re
duction is usually achieved by employing the traditional Integral-By-Parts
(IBP) relations. However\, in case of integrals with large number of scal
es\, this quickly becomes a bottleneck. In this talk\, I will show the app
lication of the recent idea\, connecting the direct decomposition of Feynm
an integrals with the Intersection theory. Specifically\, we will consider
few maximally cut Feynman integrals relevant for di-photon production on
maximal cut and show their direct decomposition to Master Integrals.\n\nht
tps://indico.cern.ch/event/783212/contributions/3512620/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512620/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Di-Higgs production in bottom quark annihilation at NNLO QCD
DTSTART;VALUE=DATE-TIME:20190910T160000Z
DTEND;VALUE=DATE-TIME:20190910T162500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512569@indico.cern.ch
DESCRIPTION:Speakers: Ravindran Vajravelu (The Institute of Mathematical S
ciences)\nWe present NNLO QCD corrections to production of pair of \nHigg
s bosons in bottom quark annihilation at the Large Hadron Collider.\nWe ta
ke into account all the partonic channels in five flavour scheme.\nWe find
that these corrections are important for the reliable predictions\nwhich
are less sensitive to unphysical scales.\n\nhttps://indico.cern.ch/event/7
83212/contributions/3512569/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512569/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Exploring the Higgs sector via Higgs boson pair production
DTSTART;VALUE=DATE-TIME:20190910T153000Z
DTEND;VALUE=DATE-TIME:20190910T155500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512604@indico.cern.ch
DESCRIPTION:Speakers: Gudrun Heinrich (Max Planck Institute for Physics)\n
We show how anomalous trilinear Higgs boson couplings\, as well as other a
nomalous couplings in the Higgs sector\, impact the shapes of distribution
s in Higgs boson pair production. In particular we discuss the interplay b
etween higher order QCD corrections and effects from physics beyond the St
andard Model\, parametrized by Effective Field Theory. We present new met
hods\, partly based on machine learning\, to extract information about th
e underlying BSM parameter space from di-Higgs observables.\n\nhttps://ind
ico.cern.ch/event/783212/contributions/3512604/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512604/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Probing the scalar potential via double Higgs boson production at
hadron colliders
DTSTART;VALUE=DATE-TIME:20190910T150000Z
DTEND;VALUE=DATE-TIME:20190910T152500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512626@indico.cern.ch
DESCRIPTION:Speakers: Ambresh Shivaji (IISER Mohali)\nIndependent Measurem
ents of Higgs self-couplings are crucial to probe new physics effects in t
he Higgs sector. Gluon fusion is the dominant mode for double Higgs produc
tion at hadron colliders. At leading order it is sensitive to the trilinea
r Higgs self-coupling. At higher orders in electroweak theory\, it also be
comes sensitive to the quartic coupling. We present a sensitivity study on
the cubic and quartic self couplings in double Higgs production. Consider
ing the relevant operators in the Standard Model Effective Field Theory up
to dimension eight\, we calculate the dominant contributions up to two-lo
op level.\n\nhttps://indico.cern.ch/event/783212/contributions/3512626/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512626/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Non-leptonic B-decays at two-loops in QCD Factorisation
DTSTART;VALUE=DATE-TIME:20190910T133000Z
DTEND;VALUE=DATE-TIME:20190910T135500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512553@indico.cern.ch
DESCRIPTION:Speakers: Tobias Huber (University of Siegen)\nI will present
the calculation of and results for the two-loop penguin amplitudes appeari
ng in non-leptonic B-decays in the framework of QCD Factorisation. I will
discuss the details of the computation of this genuine two-loop\, two-scal
e problem\, focusing i) on the analytic computation of the master integral
s and ii) on the (partially analytic) convolution of the hard kernel with
the distribution amplitude of the light final-state meson. I will present
phenomenological results\, with the two-loop correction included\, for bra
nching ratios and direct CP-asymmetries of penguin-dominated non-leptonic
B-decays.\n\nhttps://indico.cern.ch/event/783212/contributions/3512553/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512553/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Completing the four-body contributions to $\\bar{B}\\rightarrow X_
s \\gamma$ at NLO
DTSTART;VALUE=DATE-TIME:20190910T130000Z
DTEND;VALUE=DATE-TIME:20190910T132500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512578@indico.cern.ch
DESCRIPTION:Speakers: Lars-Thorben Moos ()\nThe inlusive radiative $\\bar{
B}\\rightarrow$ $X_s \\gamma$ decay constitutes an important pillar in the
indirect search for new physics and allows to constrain the parameter spa
ce of many models.\nIn this talk we present the ongoing efforts in the com
putation of four-body contributions to the process $\\bar{B}\\rightarrow$
$X_s \\gamma$\, namely those of $b\\ \\rightarrow s\\bar{q}q\\gamma$ at NL
O in the strong coupling and the necessary complementing 5-particle cuts o
f the gluon-bremsstrahlung $b\\rightarrow s\\bar{q}q\\gamma+g$.\nAlthough
these corrections are expected to be small\, this computation formally com
pletes the NLO contributions to $\\bar{B}\\rightarrow$ $X_s \\gamma$.\nSin
ce the anomalous dimensions are already computed to a sufficient order\, t
he main tasks are the systematic generation of the 1-loop amplitude\, the
automation of the phase space integration\, the infrared-regularization an
d finally the renormalization of the diagrams including the operator mixin
g.\nThe results obtained so far are shown and the further structure of the
calculation is outlined.\n\nhttps://indico.cern.ch/event/783212/contribut
ions/3512578/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512578/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Recent developments in q_T subtraction: EW corrections and power s
uppressed contributions
DTSTART;VALUE=DATE-TIME:20190910T123000Z
DTEND;VALUE=DATE-TIME:20190910T125500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512598@indico.cern.ch
DESCRIPTION:Speakers: Luca Buonocore (INFN - National Institute for Nuclea
r Physics)\nqT subtraction represents a well established and successful fo
rmalism to deal with the computation of QCD radiative corrections up to NN
LO (and beyond) for a large class of processes relevant at the LHC. We hav
e explored the possibility to extend qT subtraction to the computation of
EW corrections with the (final) aim to develop a subtraction formalism sui
table for the computation of mixed QCDXEW corrections. We present numerica
l results for the complete NLO EW corrections to the Drell-Yan production
of a massive lepton pair.\nFurthermore\, we have investigated the structur
e of the power suppressed contributions at small-qT in this process and pr
esent new analytical results on the effects of the soft radiation emitted
off a charged massive final state.\n\nhttps://indico.cern.ch/event/783212/
contributions/3512598/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512598/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Welcome
DTSTART;VALUE=DATE-TIME:20190909T070000Z
DTEND;VALUE=DATE-TIME:20190909T071500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3523901@indico.cern.ch
DESCRIPTION:Speakers: The Organizers ()\nhttps://indico.cern.ch/event/7832
12/contributions/3523901/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3523901/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mixed QCD x QED Corrections to Drell-Yan Z Production
DTSTART;VALUE=DATE-TIME:20190910T100000Z
DTEND;VALUE=DATE-TIME:20190910T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512601@indico.cern.ch
DESCRIPTION:Speakers: Ignacio Fabre (ICAS-UNSAM)\nWhen computing perturbat
ive corrections to a process QCD provides the phenomenologically most sign
ificant contribution. Nevertheless\, because of the similar size of $\\alp
ha_S^2$ respect to $\\alpha_{QED}$\, for a precision prediction one needs
to consider electroweak corrections as well.\nIn this talk we show how one
can obtain the mixed QCDxQED corrections from pure QCD NNLO corrections b
y means of an abelianization procedure. We show this by explicitly applyin
g such procedure to the production of an on-shell Z boson in hadronic coll
isions. This way\, we profit from a legacy 20-year-old NNLO calculation to
extend the available knowledge up to complete QCD⊕QED NNLO order.\n\nht
tps://indico.cern.ch/event/783212/contributions/3512601/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512601/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mixed EW-QCD two-loop corrections to Drell-Yan production
DTSTART;VALUE=DATE-TIME:20190910T093000Z
DTEND;VALUE=DATE-TIME:20190910T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512605@indico.cern.ch
DESCRIPTION:Speakers: Matthias Heller ()\nThe Drell-Yan production of char
ged lepton pairs is one of the key processes measured at hadron colliders.
The QCD corrections to the cross-section are known to order $\\alpha_s^2$
and electroweak corrections are known to order $\\alpha$. The next import
ant step for a better theoretical understanding is the complete calculatio
n of the mixed QCD-EW corrections of order $\\alpha_s \\alpha$. In this ta
lk\, I report on the first calculation of the virtual two-loop corrections
of order $\\alpha_s\\alpha$ to the cross-section. The calculation is carr
ied out analytically using tensor reduction\, IBP relations and the method
of differential equations. We validate a previous calculation of the subs
et of mixed QCD-QED corrections and show how the jet and soft functions of
that reference can be used to subtract the infrared divergencies of the c
omplete mixed QCD-electroweak virtual corrections.\n\nhttps://indico.cern.
ch/event/783212/contributions/3512605/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512605/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Mixed EW-QCD corrections to the higgs decay into bottom quarks
DTSTART;VALUE=DATE-TIME:20190910T090000Z
DTEND;VALUE=DATE-TIME:20190910T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512616@indico.cern.ch
DESCRIPTION:Speakers: Ulrich Schubert ()\nAfter the discovery of the Higgs
boson the precise determination of its properties has become a priority.
These precision studies often involve the decay of the Higgs boson to bott
om quarks\, since it is the predominately decay channel. In this talk I w
ill present the calculation of the exact mixed EW-QCD corrections to this
decay\, which improves upon the existing approximate calculation. In parti
cular I will elaborate on the treatment of $\\gamma_5$\, the calculation o
f the exact master integrals and the renormalization procedure. I will con
clude by presenting how this inclusive calculation could be extended to di
fferential observables.\n\nhttps://indico.cern.ch/event/783212/contributio
ns/3512616/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512616/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Towards 2 -> 3 NNLO QCD calculations
DTSTART;VALUE=DATE-TIME:20190910T100000Z
DTEND;VALUE=DATE-TIME:20190910T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512599@indico.cern.ch
DESCRIPTION:Speakers: Rene Poncelet (Cambridge University)\nPrecise predic
tions for total and differential cross sections\nat hadron colliders becam
e an important corner stone of the LHC physics.\nThe lack of new 'smoking-
gun' physics signals\nrequires precise comparisons between measurements an
d Standard Model\npredictions to get a\nhandle on new physics effects. Tre
mendous efforts have been made to push\nperturbative calculations to highe
r orders such that NNLO QCD calculations are\nnow state-of-art for most 2
$\\to$ 1 and 2 $\\to$ 2 hard scattering processes.\nUpcoming five-point tw
o-loop amplitudes and refined subtractions schemes for\nreal radiation con
tributions allow first steps in the direction of 2 $\\to$ 3\nscattering pr
ocesses.\nI present novel NNLO QCD results for 2 $\\to$ 3 processes obtain
ed with the\nSector-improved Subtraction Scheme and their phenomenological
application.\n\nhttps://indico.cern.ch/event/783212/contributions/3512599
/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512599/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Infrared structure of N=4 SYM and Leading trancendentality princip
le in gauge theory
DTSTART;VALUE=DATE-TIME:20190910T093000Z
DTEND;VALUE=DATE-TIME:20190910T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512614@indico.cern.ch
DESCRIPTION:Speakers: Amlan Chakraborty (The Institute of Mathematical Sci
ences\, HBNI\, Taramani\, Chennai-600113\, India)\nIn this talk\, we prese
nt a detailed study on the infrared structure of N=4 SYM and its connectio
n to QCD. Calculation of collinear splitting functions helps to understand
the structure and thus one can get infrared safe cross sections. We also
demonstrate the factorization property that soft plus virtual part of the
cross section satisfies and through factorization\, we calculate soft dist
ribution function up to third order in perturbation theory. We show that t
he soft distribution function is process independent that includes operato
rs as well as external legs unlike QCD. In addition to this we analyse our
findings against the known results in QCD through principle of maximum tr
anscendentality and we extend our analysis further for the case of three p
oint form factors involving several gauge invariant operators.\n\nhttps://
indico.cern.ch/event/783212/contributions/3512614/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512614/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The R*-method: Recent applications and developments
DTSTART;VALUE=DATE-TIME:20190910T090000Z
DTEND;VALUE=DATE-TIME:20190910T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512546@indico.cern.ch
DESCRIPTION:Speakers: Franz Herzog (Nikhef)\nThe R*-method is a powerful t
ool to calculate anomalous dimensions of local QFTs. I will present new r
esults which have been obtained with the method\, such as the first few Me
llin moments of splitting functions at N4LO\, which also allowed us to obt
ain a first numerical estimate of the cusp anomalous dimension at five loo
ps\, and a calculation of the anomalous dimension of Weinberg's dimension-
6 gluonic operator at 2 and 3 loops which is relevant for EDM measurements
. Furthermore\, I will present a new Hopf algebraic formulation which gene
ralizes the Connes-Kreimer Hopf algebra.\n\nhttps://indico.cern.ch/event/7
83212/contributions/3512546/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512546/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NNLO mixed EW-QCD corrections to single vector boson production
DTSTART;VALUE=DATE-TIME:20190910T080000Z
DTEND;VALUE=DATE-TIME:20190910T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512589@indico.cern.ch
DESCRIPTION:Speakers: Narayan Rana (INFN Milan)\nIn this talk\, we outline
the computational details to obtain mixed EW-QCD corrections to on-shell
production of a single vector boson at the LHC at two-loop level. We use t
he novel method of differential equation to obtain the pure virtual\, real
-virtual and double-real master integrals.\n\nhttps://indico.cern.ch/event
/783212/contributions/3512589/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512589/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Top-quark hadroproduction in NNLO QCD
DTSTART;VALUE=DATE-TIME:20190910T073000Z
DTEND;VALUE=DATE-TIME:20190910T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512592@indico.cern.ch
DESCRIPTION:Speakers: Simone Devoto (UZH)\nThe study of top-quark producti
on and decay is central in the LHC physics programme\, allowing precise te
sts of the Standard Model and offering a window on possible new physics. A
ccurate theoretical predictions are crucial for these analyses. In this ta
lk\, we report on a new calculation of the next-to-next-to-leading order Q
CD radiative corrections to the production of top-quark pairs at hadron co
lliders. The calculation is performed by using the qT-subtraction method t
o handle and cancel infrared singular contributions at intermediate stages
of the computation\, and represents its first complete application to the
hadroproduction of a colourful high-mass system at next-to-next-to-leadin
g order. We discuss the calculation of the additional soft contributions n
eeded to implement qT subtraction for this process\, and show first numeri
cal results.\n\nhttps://indico.cern.ch/event/783212/contributions/3512592/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512592/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Fiducial differential cross sections at the LHC and their future a
pplications
DTSTART;VALUE=DATE-TIME:20190910T070000Z
DTEND;VALUE=DATE-TIME:20190910T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512577@indico.cern.ch
DESCRIPTION:Speakers: Xuan Chen (Universitaet Zuerich (CH))\nFiducial diff
erential cross sections are reliable observables that the LHC is providing
more and more precise measurements. From the theory point of view\, event
generators could simulate the underlying processes and apply the same exp
erimental selection criterion to reduce the systematical errors when compa
ring with data. I will introduce some of the implementations and simulatio
ns from NNLOJET package with the-state-of-the-art theory precisions at NNL
O QCD and above then illustrate their future applications when comparing w
ith LHC data.\n\nhttps://indico.cern.ch/event/783212/contributions/3512577
/
LOCATION: Cubiculaire
URL:https://indico.cern.ch/event/783212/contributions/3512577/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analytic Two-Loop Five-Parton QCD Amplitudes from Numerical Unitar
ity
DTSTART;VALUE=DATE-TIME:20190910T080000Z
DTEND;VALUE=DATE-TIME:20190910T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512551@indico.cern.ch
DESCRIPTION:Speakers: Vasily Sotnikov (University of Freiburg)\nWe present
the analytic form of all two-loop five-parton helicity amplitudes require
d for the calculation of NNLO QCD corrections to the production of three j
ets at hadron colliders in the leading-color approximation. The results ar
e analytically reconstructed from exact numerical evaluations over finite
fields. We employ a number of physics-motivated ideas to facilitate the re
construction\, as well as an optimized approach to the numerical treatment
of particle states in $D$ dimensions. This allows to obtain the analytica
l expressions with a modest computational effort. Systematic simplificatio
n of the amplitudes using multivariate partial-fraction decomposition lead
s to a particularly compact form.\n\nhttps://indico.cern.ch/event/783212/c
ontributions/3512551/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512551/
END:VEVENT
BEGIN:VEVENT
SUMMARY:On the choice of variables in IBP reductions
DTSTART;VALUE=DATE-TIME:20190910T073000Z
DTEND;VALUE=DATE-TIME:20190910T075500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512631@indico.cern.ch
DESCRIPTION:Speakers: Jos Vermaseren ()\nAs part of a project to derive pa
rametric reduction schemes automatically a\nsystematic search has been set
up to determine 'good sets of variables'. It\nturns out that both the eas
e of derivation of a scheme and its efficiency\ndepend very sensitively on
the choice of variables. For some topologies\nthere can be thousands of s
uch choices. I report here on this search and\nthe resulting automatic der
ivations of practical schemes. As an example I\nuse four loop massless pro
pagator topologies\, but the results are\napplicable for more complicated
reactions with fewer loops as well.\n\nhttps://indico.cern.ch/event/783212
/contributions/3512631/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512631/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Syzygies for no-numerator or no-dot relations between Feynman inte
grals
DTSTART;VALUE=DATE-TIME:20190910T070000Z
DTEND;VALUE=DATE-TIME:20190910T072500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512597@indico.cern.ch
DESCRIPTION:Speakers: Andreas von Manteuffel (Michigan State University)\n
In this talk I will discuss new algorithmic approaches to reduce Feynman i
ntegrals. Syzygies derived in the Lee-Pomeransky and the Baikov representa
tion allow to find linear relations\, which avoid the introduction of eith
er irreducible numerators or higher powers of propagators\, respectively.
The relevant syzygies can be calculated with linear algebra methods based
on finite fields. These techniques have been applied to calculate quark an
d gluon form factors in four-loop QCD as well as multi-scale two-loop ampl
itudes.\n\nhttps://indico.cern.ch/event/783212/contributions/3512597/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512597/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Quark and gluon jet functions at 3-loops in QCD
DTSTART;VALUE=DATE-TIME:20190909T163000Z
DTEND;VALUE=DATE-TIME:20190909T165500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512621@indico.cern.ch
DESCRIPTION:Speakers: Prasanna K. Dhani (INFN\, Florence)\nI will talk abo
ut the recent computation of three loop jet functions (arXiv:1805.02637) i
n perturbative QCD. These results have been extracted from the known three
loop coefficient functions for deep-inelastic scattering via the exchange
of a virtual photon that couples to quarks or a scalar that couples to gl
uons and employing renormalization group invariance and factorization theo
rem. We obtain both the quark and the gluon jet functions up to three loop
level. These jet functions being universal ingredients in the SCET framew
ork\, will play an important role in the phenomenological studies at the L
HC\, such as resummation of jet observables and also in subtraction method
s.\n\nhttps://indico.cern.ch/event/783212/contributions/3512621/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512621/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Analytic multi-loop results using finite fields and dataflow graph
s with FiniteFlow
DTSTART;VALUE=DATE-TIME:20190909T153000Z
DTEND;VALUE=DATE-TIME:20190909T155500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512622@indico.cern.ch
DESCRIPTION:Speakers: Tiziano Peraro ()\nI will describe FiniteFlow\, a fr
amework for defining and executing numerical algorithms over finite fields
and reconstructing analytically multivariate rational functions. The fra
mework employs computational graphs\, known as dataflow graphs\, to combin
e basic building blocks into complex algorithms. This allows to easily im
plement a wide range of methods over finite fields in high-level languages
and computer algebra systems\, without being concerned with the low-level
details of the numerical implementation. This approach sidesteps the appe
arance of large intermediate expressions and can be massively parallelized
. I will show recent applications of this framework\, such as analytic re
sults for two-loop five-point scattering and for the four-loop cusp anomal
ous dimension.\n\nhttps://indico.cern.ch/event/783212/contributions/351262
2/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512622/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Simple differential equations for Feynman integrals associated to
elliptic curves
DTSTART;VALUE=DATE-TIME:20190909T150000Z
DTEND;VALUE=DATE-TIME:20190909T152500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512571@indico.cern.ch
DESCRIPTION:Speakers: Stefan Weinzierl (Universität Mainz)\nI will discus
s Feynman integrals\, which are associated to elliptic curves and their di
fferential equations. I will show for non-trivial examples how the system
of differential equations can be brought into an $\\varepsilon$-form. Sing
le-scale and multi-scale cases will be discussed.\n\nhttps://indico.cern.c
h/event/783212/contributions/3512571/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512571/
END:VEVENT
BEGIN:VEVENT
SUMMARY:NNLO local analytic subtraction for final state radiation (and bey
ond)
DTSTART;VALUE=DATE-TIME:20190909T133000Z
DTEND;VALUE=DATE-TIME:20190909T135500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512617@indico.cern.ch
DESCRIPTION:Speakers: Sandro Uccirati (INFN - National Institute for Nucle
ar Physics)\nI present the complete results of "Torino" local analytic sub
traction of infrared divergences from final state real radiation at NNLO i
n QCD and report the progresses for the analogous treatment of the radiati
on from the initial state.\n\nhttps://indico.cern.ch/event/783212/contribu
tions/3512617/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512617/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Precision Event Shapes at the LHC: the Transverse Energy-Energy Co
rrelator in the Back-to-Back Limit
DTSTART;VALUE=DATE-TIME:20190909T130000Z
DTEND;VALUE=DATE-TIME:20190909T132500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512625@indico.cern.ch
DESCRIPTION:Speakers: HuaXing Zhu ()\nWe present an operator based factori
zation formula for the transverse energy-energy correlator (TEEC) hadron c
ollider event shape in the back-to-back (dijet) limit. This factorization
formula exhibits a remarkably symmetric form\, being a projection onto a s
cattering plane of a more standard transverse momentum dependent factoriza
tion. Soft radiation is incorporated through a dijet soft function\, which
can be elegantly obtained to next-to-next-to-leading order (NNLO) due to
the symmetries of the problem. We present numerical results for the TEEC r
esummed to next-to-next-to-leading logarithm (NNLL) matched to fixed order
at the LHC. Our results constitute the first NNLL resummation for a dijet
event shape observable at a hadron collider\, and the first analytic resu
lt for a hadron collider dijet soft function at NNLO. We anticipate that t
he theoretical simplicity of the TEEC observable will make it indispensabl
e for precision studies of QCD at the LHC\, and as a playground for theore
tical studies of factorization and its violation.\n\nhttps://indico.cern.c
h/event/783212/contributions/3512625/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512625/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Five-Point Two-Loop Amplitudes Beyond the Planar Limit
DTSTART;VALUE=DATE-TIME:20190909T123000Z
DTEND;VALUE=DATE-TIME:20190909T125500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512633@indico.cern.ch
DESCRIPTION:Speakers: Ben Page (IPhT\, CEA-Saclay)\nScattering amplitudes
in supersymmetric theories are known to display many remarkable structures
\, but most higher loop results are limited to planar theories. In this ta
lk we discuss the structure of the recent\, symbol-level\, results for the
N=4 SYM amplitude with full colour dependence and the N=8 SUGRA amplitude
. We elaborate on the modern\, ansatz-based\, approach to the calculation.
Leading singularities in both 4 and $d$-dimensions are used to construct
a set of rational prefactors upon which the amplitudes are numerically dec
omposed using finite-field arithmetic.\n\nhttps://indico.cern.ch/event/783
212/contributions/3512633/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512633/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Soft-gluon effective coupling and cusp anomalous dimension
DTSTART;VALUE=DATE-TIME:20190909T100000Z
DTEND;VALUE=DATE-TIME:20190909T102500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512586@indico.cern.ch
DESCRIPTION:Speakers: Massimiliano Grazzini (Universitaet Zuerich (CH))\nW
e consider the extension of the CMW soft-gluon effective coupling beyond t
he next-to-leading logarithmic accuracy. We present two proposals of a sof
t-gluon effective coupling that extend the CMW coupling to all perturbativ
e orders. Although both effective couplings are well-defined in four dimen
sions\, we examine their behaviour in d=4-2epsilon dimensions. We uncover
an all-order perturbative relation with the cusp anomalous dimension: the
(four dimensional) cusp anomalous dimension is equal to the d-dimensional
soft-gluon effective coupling at the conformal point epsilon=beta(alphas)\
, where the d-dimensional QCD beta-function\, vanishes. We present the exp
licit expressions of the two soft-gluon couplings up to O(alphas^2) in d d
imensions. In the four-dimensional case we compute the two soft couplings
up to O(alphas^3). For one of the two couplings\, we confirm the O(alphas^
3) result previously presented by other authors. For the other coupling\,
we obtain the explicit relation with the cusp anomalous dimension up to O(
alphas^4). We comment on Casimir scaling at O(alphas^4).\n\nhttps://indico
.cern.ch/event/783212/contributions/3512586/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512586/
END:VEVENT
BEGIN:VEVENT
SUMMARY:The High-Energy Limit of 2 to 2 Partonic Scattering Amplitudes
DTSTART;VALUE=DATE-TIME:20190909T093000Z
DTEND;VALUE=DATE-TIME:20190909T095500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512627@indico.cern.ch
DESCRIPTION:Speakers: Einan Gardi (The University of Edinburgh)\nRecently\
, there has been significant progress in computing scattering amplitudes i
n the high-energy limit using rapidity evolution equations. I describe the
state-of-the-art and demonstrate the interplay between exponentiation of
high-energy logarithms and that of infrared singularities. \nThe focus in
this talk is the imaginary part of 2 to 2 partonic amplitudes\, which can
be determined by solving the BFKL equation. I demonstrate that the wavefun
ction is infrared finite\, and that its evolution closes in the soft appro
ximation. Within this approximation I derive a closed-form solution for th
e amplitude in dimensional regularization\, which fixes the soft anomalous
dimension to all orders at NLL accuracy. \nI then turn to finite contribu
tions of the amplitude and show that the remaining `hard’ contributions
can be determined algorithmically\, by iteratively solving the BFKL equati
on in exactly two dimensions within the class of single-valued harmonic po
lylogarithms. \nTo conclude I present numerical results and analyse large
-order behaviour of the amplitude.\n\nhttps://indico.cern.ch/event/783212/
contributions/3512627/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512627/
END:VEVENT
BEGIN:VEVENT
SUMMARY:LHC observables with NNLOJET
DTSTART;VALUE=DATE-TIME:20190909T080000Z
DTEND;VALUE=DATE-TIME:20190909T082500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512529@indico.cern.ch
DESCRIPTION:Speakers: Aude Gehrmann-De Ridder (ETH Zurich)\nIn this talk\
, I aim to review the phenomenology of LHC observables\, related to proces
ses newly implemented in the NNLOJET parton level event generator.\n\nhttp
s://indico.cern.ch/event/783212/contributions/3512529/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512529/
END:VEVENT
BEGIN:VEVENT
SUMMARY:Hidden Analytic Structure of Two-Loop Higgs Amplitudes
DTSTART;VALUE=DATE-TIME:20190909T090000Z
DTEND;VALUE=DATE-TIME:20190909T092500Z
DTSTAMP;VALUE=DATE-TIME:20190921T084917Z
UID:indico-contribution-783212-3512554@indico.cern.ch
DESCRIPTION:Speakers: Gang Yang ()\nThe discovery of a standard-model-like
Higgs boson at LHC set a milestone in particle physics. For probing poten
tial new physics beyond the Standard Model as well as understanding the de
tails of Higgs physics\, the high precision computation of Higgs amplitude
s is mandatory. We obtain the two-loop Higgs plus three-parton amplitudes
with high dimension operators in Higgs effective field theory. While effic
ient new methods have been developed in the computation\, a particular foc
us will be on the analytic structure of the results\, which take remarkabl
y simple form and show hidden relations. In particular\, the results satis
fy the so-call maximal transcendentality principle\, which conjectures tha
t QCD and N=4 SYM results share the same leading transcendental parts. The
simplicity of the results and the surprising correspondence indicate ther
e may be further hidden analytic structure to be uncovered which hopefully
may lead to a better way in computation in practice. We will discuss the
correspondence as well as the possible impact.\n\nhttps://indico.cern.ch/e
vent/783212/contributions/3512554/
LOCATION: Chambre du Trésorier
URL:https://indico.cern.ch/event/783212/contributions/3512554/
END:VEVENT
END:VCALENDAR