Conveners
Section E
- Marco Gersabeck (University of Manchester (GB))
Section E
- Felipe J. Llanes-Estrada (Universidad Complutense de Madrid)
- Martha Constantinou (Temple University)
- Marco Gersabeck (University of Manchester (GB))
Section E
- Felipe J. Llanes-Estrada (Universidad Complutense de Madrid)
Section E
- Achim Schwenk (TU Darmstadt)
Section E
- Emanuele Mereghetti (LANL)
Description
Section E: QCD and New Physics
Physics beyond the Standard Model with hadronic physics precision experimental data and precision calculations.
Conveners: W. Detmold (MIT), M. Gersabeck (U. Manchester), F. J. Llanes-Estrada (UC Madrid), E. Mereghetti (Los Alamos NL), J. Portoles (IFIC, Valencia)
Rare electroweak penguin processes provide a rich platform to search for new physics. Some deviations have recently been found between the rate and angular distribution of these processes measured by the LHCb experiment and theoretical predictions. In addition, LHCb has seen hints of lepton universality breaking in these rare processes. This talk will review these measurements and put them in...
I review the theory of the search for new physics with rare flavour-changing processes, some of which may indicate departures from the Standard Model, with an emphasis on the Standard-Model predictions and their uncertainties. I will focus on semileptonic B decays, but will also discuss recent developments and prospects in K physics.
The LHC has found several anomalies in exclusive semileptonic b --> s mu mu decays with a global significance of more than 4 sigma. I will discuss the hadronic uncertainties entering the theoretical prediction for the relevant decays and present model-independent global fits of new physics to the data. The discrimination between high-scale new physics and low-energy QCD effects, as well as the...
Lattice QCD calculations with dynamical fermions are getting more and more precise in recent years. The uncertainties of lattice QCD results can be shrinked systematically. I will discuss lattice QCD calculations of weak matrix elements related to quark flavor anomalies in bottom quark decays.
In this talk, the latest results of searches for the standard model Higgs boson produced in association with a top quark-antiquark pair (ttH), where Higgs decays into photons, bottom quark-antiquark pair or leptons via WW, ZZ and tautau will be presented. The analyses have been performed using the 13 TeV pp collisions data recorded by the CMS experiment in 2015. The results are presented in...
The top quark is the heaviest known fundamental particle. As it is the only quark that decays before it hadronizes, this gives us the unique opportunity to probe the properties of bare quarks and to test perturbative QCD. This talk will focus on a few recent precision top quark measurements by the ATLAS Collaboration: fiducial top pair and single top production cross sections including...
coupling constant, nonperturbative QCD parameter, dispersive model.
If the Higgs boson discovered at the LHC is not exactly the one predicted
by the Standard Model the theory becomes strongly coupled at high energy
and vector boson scattering violates unitarity in the TeV range. This can
be regularised by the introduction of new heavy resonances. These
resonances may also couple to quark pairs and can be searched for in their
decay to vector or Higgs...
The WZ boson pair production at 13 TeV is measured using the ATLAS detector. Leptonic decays of the W and Z bosons to electrons and muons are considered using 2015 and 2016 data. The differential cross-section as a function of jet multiplicity, the Z-boson pT and the transverse mass of the WZ system are also measured along with the charge-dependent W+Z and W-Z cross-sections and their ratio....
Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale.
The ATLAS collaboration has measured inclusive and differential cross sections of the production of ZZ pairs in final states with four...
The properties of the QCD axion are strictly related to the
dependence of the theory on the topological parameter theta.
We will present a determination of the topological properties of QCD for
temperatures up to around 600MeV, obtained by lattice QCD simulations
with 2+1 flavors and physical quark masses. Numerical results for
the topological susceptibility, when compared to instanton...
The determination of quark masses from lattice QCD simulations requires a non-perturbative renormalization procedure and subsequent scale evolution to high energies, where a conversion to the commonly used $\overline{\rm MS}$ scheme can be safely established. We present our results for the non-perturbative running of renormalized quark masses in $N_{\rm f}=3$ QCD between the electroweak and a...
The study of the couplings of the Higgs boson and of the top quark plays a preeminent role at the LHC, and could unveil the first signs of new physics. I will discuss the interplay of direct and indirect probes of certain classes of top and Higgs couplings. Including constraints from collider observables, precision electroweak tests, flavor physics, and electric dipole moments (EDMs), I will...
The anomalous magnetic moment of the muon $(g-2)_\mu$ has been measured and computed to very high precision of about 0.5 ppm. For more than a decade, a discrepancy has persisted between experiment and Standard Model prediction, now of about $3\sigma$. The main uncertainty of the theory prediction is due to strong interaction effects. With the expected improvement of the input for hadronic...
The Muon g-2 Experiment at Fermilab aims to measure the anomalous magnetic moment of the muon to a precision of 140 parts per billion. This four-fold improvement over the previous Brookhaven E821 measurement provides significant insight into the tantalizing 3.5 standard deviation discrepancy between measurement and the Standard Model prediction
The measurement of the anomalous magnetic moment...
The Qweak experiment, which ran for two and a half years at Jefferson Lab,
will precisely determine the weak charge of the proton by measuring the
parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a
longitudinally polarized electron beam and a liquid hydrogen target at a
low momentum transfer of $Q^2 = 0.025 \left(\textrm{GeV/c} \right)^2$. The
weak charge of the...
In the previous decade, the topic of the nucleon's nonperturbative or $\it{intrinsic}$ charm content has enjoyed something of a renaissance, largely motivated by theoretical developments involving quark modelers and PDF-fitters. In this talk I will briefly describe the importance of intrinsic charm to various issues in high-energy phenomenology, and survey recent progress in constraining its...
Current experiments aim at measuring parameters of Standard Model to an unprecedented accuracy, and as a consequence require theoretical calculations of radiative corrections that match that precision. The so-called dispersion corrections, or hadronic box corrections represent one of the main limitations of the reach of modern experiments in determining SM parameters and constraining the New...
Experimental measurements of muonic hydrogen bound states have recently started to take place and provide a powerful setting in which to study the properties of QCD. We profit of the power of effective field theories (EFTs) to provide a theoretical setting in which to study muonic hydrogen in a model independent fashion. In particular, we compute expressions for the Lamb shift and the...
Permanent Electric Dipole Moments (EDM) of hadrons and leptons provide a unique probe for physics beyond the Standard Model (SM). As EDMs violate P and T symmetries, they also provide information about the matter-antimatter asymmetry in the universe. Although the SM prediction for EDMs is beyond the reach of current experiments, the experiments set stringent limits on many beyond SM models. In...
I will provide an overview of various leading contributions to neutron electric dipole moment (EDm) from both the standard model and beyond the standard model and then summarize the status of lattice QCD calculations of the matrix elements of two of the leading novel CP violating interactions -- the quark EDM and the quark chromo EDM.
Permanent electric dipole moments (EDMs) are sensitive probes of CP violation beyond the Standard Model. EDM experiments typically involve complicated systems such as hadrons, nuclei, and atoms. I will discuss an effective field theory framework in which EDM measurements can be interpreted in terms of more fundamental concepts. As an example, I illustrate how EDM measurements set strong...
We will give an overview about the current state of the calculation of di-boson
production. For precision measurements at the LHC both NNLO QCD and NLO EW
corrections are important. The Di-boson production processes give access to
triple gauge couplings and possible modifications in the form of anomalous
couplings (AC). We will present a study on WZ production with AC at approximate
NNLO...
A collaborative effort to determine the $\Lambda$-parameter in 3-flavour
QCD by the ALPHA collaboration has just been finalized. This requires the precise
connection of vastly different energy scales, which is achieved using suitable
running couplings in finite volume renormalization schemes and recursive step-scaling methods.
In this talk I focus on the scale evolution from an intermediate...
In this talk we present the ALPHA-collaboration computation of the three-flavour QCD $\Lambda$-parameter. Starting from the value of $\Lambda$ in units of an intermediate energy scale $\mu=1/L_0 \sim 4\, {\rm GeV}$ (cf. talk by S. Sint), we first discuss the connection of this scale and a given hadronic scale, $1/L_{\rm had}$, of a few hundred MeV. The latter is obtained very precisely by...
We have derived all WIMP-nucleon interactions in chiral EFT to third order in the chiral expansion, including all one- and two-body currents. Because the relevant momentum transfers involved in WIMP scattering off nuclei are of the order of the pion mass, this is a prime regime for chiral EFT.
Combined with large-scale nuclear structure calculations, we have studied spin-dependent...
In this talk we will review recent progress in hadron structure using lattice
QCD simulations, with main focus in the evaluation of nucleon matrix elements.
We will highlight developments that may guide New Physics searches, such as the
scalar/tensor charges, and neutron electric dipole moment. We will also give
updates on a new direct approach to compute quark parton distributions...
Neutrinoless double-beta decay is a lepton-number violating process that will establish that neutrinos are its own antiparticle. In the next few years, ton-scale experiments will aim for the detection of this rare decay. Naturally, the nuclear decay rate depends on the nuclear matrix element of the transition (NME). The NMEs are necessary to constrain the neutrino mass from limits on the decay...
Neutrinoless double beta decay searches play a major role in determining properties of neutrinos as well as nuclei. The double-beta decay with neutrinos is one of the rarest process in the world. It has been observed in only a few nuclei so far. The even rarer process of neutrinoless double-beta decay will have a major impact on the current Standard
model. It would show that neutrinos are...
The observed matter-antimatter asymmetry of the universe is an outstanding mystery of physics that cannot be explained within the Standard Model. Many beyond the Standard Model (BSM) explanations have been proposed, and experimental data is needed to constrain the wide theory space of BSM models. Neutron-antineutron oscillations are predicted to be a signature of some BSM baryogenesis models...
