Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): S. Honda, ATLAS collaborationAbstractAfter the discovery of the Higgs boson, the measurement of its coupling properties are of particular importance. In this talk measurement of the cross sections and couplings of the Higgs boson in bosonic and fermionic decay channels with the ATLAS detector are presented.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Eugenio Megías, Mariano Quirós, Lindber SalasAbstractWe study the recently found anomalies in B-meson decays within a scenario with a warped extra dimension where the Standard Model (SM) fermions are propagating in the bulk. The anomalies are then interpreted as the result of the exchange of heavy vector resonances with electroweak (EW) quantum numbers. The model naturally leads to lepton-flavor universality (LFU) violation when different flavor fermions are differently localized along the extra dimension, signaling a different degree of compositeness in the dual holographic theory.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): R.R. Akhmetshin, A.N. Amirkhanov, A.V. Anisenkov, V.M. Aulchenko, V.Sh. Banzarov, N.S. Bashtovoy, D.E. Berkaev, A.E. Bondar, A.V. Bragin, S.I. Eidelman, D.A. Epifanov, L.B. Epshteyn, A.L. Erofeev, G.V. Fedotovich, S.E. Gayazov, A.A. Grebenuk, S.S. Gribanov, D.N. Grigoriev, F.V. Ignatov, V.L. IvanovAbstractThis paper reports measurements of the hadronic cross sections with the CMD-3 detector at the VEPP-2000 electron-positron collider. The overall size of the data sample analyzed is about 60 pb-1, collected by the CMD- 3 running since December 2010 up to June 2013 in the c.m. energy range from 0.32 to 2.0 GeV. The preliminary results of data analysis for various modes of e+e−→hadrons are discussed.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): G. Vasseur, BABAR CollaborationAbstractThe BABAR Collaboration pursues an intensive program studying hadronic cross sections in low-energy electron-positron annihilations, accessible via initial-state radiation. Our measurements allow significant improvements in the precision of the predicted value of the muon anomalous magnetic moment. These improvements are necessary for shedding light on the current 3 σ difference between the predicted and the experimental values. We have published results on a number of processes with from two to six hadrons in the final state and other final states are currently under investigation. We report here on the most recent results obtained by analysing the entire BABAR dataset. We present in particular the measurement of the mode with two charged pions and two neutral pions and the measurement of the full set of final states with two kaons and one or two pions.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Martin Ripka, BESIII collaborationAbstractA difference of more than three standard deviations between is currently observed between the direct experimental measurement and the Standard Model prediction of the anomalous magnetic moment of the muon (g−2)μ. The hadronic vacuum polarization contributions can be related to hadronic cross sections using the optical theorem. Precision measurements of the hadronic cross sections e+e−→π+π−, π+π−π0, π+π−2π0, ωπ0 and π+π−3π0 are performed at the BESIII experiment located in Beijing, China. The initial state radiation method is used to access the energy regions of interest for (g−2)μ. Our results will improve the precision of the Standard Model prediction of (g−2)μ.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Yuping Guo, BESIII CollaborationAbstractThe anomalous magnetic momentum of muon, aμ, has been measured in experiment and calculated in theory with a precision up to ∼0.5 ppm. But there is a long standing 3 to 4 standard deviations between these two accurate values. The dominant contribution to the uncertainty in the theoretical calculation comes from the hadroninc contribution, including contributions from the hadronic vacuum polarization and the hadronic light-by-light. The meson transition form factors measured in two photon process at BESIII can be used as input or constrain for the calculation of the hadronic light-by-light contribution to aμ. Recent experimental activities, including the measurements of the transition form factor of π0, η, and η′, and the cross section of γγ⁎→π+π− are presented.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): O.V. Teryaev, V.I. ZakharovAbstractWe consider the problem of transferring overall rotation of quark-gluon plasma to polarization of hyperons along the rotation axis. As a toy theoretical model, we exploit that of pionic superfluidity induced by chemical potentials violating isotopic symmetry. Apparently, the model accounts only for the light degrees of freedom, that is pions. The rotation, however, results in vortices which are infinitely thin in the hydrodynamic approximation. Field theory resolves the singularity and predicts that the core of the vortices is build up on spins of baryons. We review consequences from the quark-hadron duality in this case. First, an anomalous triangle graph in effective field theory turns to be dual to the vorticity term in the standard hydrodynamic expansion. And, then, the overall coefficient determining the polarization of baryons is fixed by duality with the triangle graph in the fundamental field theory.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): J.P. Carlomagno, M. LoeweAbstractWe compare two order parameters for the deconfinement transition, induced by thermal and density effects, commonly used in the literature, namely the thermal and density evolution of the continuum threshold s0, within the frame of the QCD sum rules, and the trace of the Polyakov loop Φ in the framework of a nonlocal S U(2) chiral quark model. We include in our discussion the evolution of the chiral quark condensate, the parameter that characterizes the chiral symmetry restoration. We found that essentially both order parameters, s0 and Φ, provide the same information for the deconfinement transition, both for the zero and finite chemical potential cases. At zero density, the critical temperatures in both cases coincide exactly and, in the case of finite baryonic chemical potential μ, we find evidence for the appearance of a quarkyonic phase.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): César AyalaAbstractWe consider a phenomenologycal parametrization of the QCD running coupling which arises from the dispersion relation respecting the holomorphic properties of the physical QCD observables in the complex momentum plane. The parameters are fixed by the following requirements: 1) at enough high energies, it reproduces the underlying perturbative coupling, 2) at intermediate energy momenta, it reproduces the experimental semihadronic tau decay ratio, and 3) in the deep IR regime, it satisfies the qualitative properties coming from recent lattice results. Finally, we apply this new coupling to low-energy available experimental data. In particular, to Borel sum rules for τ-decay, extracting the values of the dimension 4 and 6 condensates, to the V-channel Adler function, and to polarized Bjorken Sum Rule.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Marco FrascaAbstractWe solve exactly the Dyson-Schwinger equations for Yang-Mills theory in 3 and 4 dimensions. This permits us to obtain the exact correlation functions till order 2. In this way, the spectrum of the theory is straightforwardly obtained and comparison with lattice data can be accomplished. The results are in exceedingly good agreement with an error well below 1%. This extends both to 3 and 4 dimensions and varying the degree of the gauge group. These results provide a strong support to the value of the lattice computations and show once again how precise can be theoretical computations in quantum field theory.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): M. Ahmady, F. Chishtie, R. SandapenAbstractWe report that the pion radius, decay constant, EM and transition form factors can simultaneously and accurately be predicted in light-front holographic QCD with a universal AdS/QCD mass scale, provided dynamical spin effects are taken into account.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Huan-Huan Liu, BESIII CollaborationAbstractThe BESIII has collected 1.3 billion J/ψ and 478 million ψ(3686) data since 2009. In this talk, we will introduce five recent analyses on light hadron spectroscopy at BESIII, including two studies on the X(1835), two partial wave analyses that are related to searching and studying glueball candidates, and one study on χc1.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Li GongAbstractA sample of 1.3 × 109J/ψ events collected with BESIII detector at the BEPCII provide us a sample of η and η′ for decay studies, this paper reviews the latest η and η′ related results from BESIII, including dalitz plot analysis of η→π+π−π0 and η/η′→π0π0π0, amplitude analysis of η′→3π, double radiative decay of η′→γγπ0 and the weak decay η′→Kπ.

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Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Bin-Long WangAbstractUsing 567 pb-1 of e+e− annihilation data collected at a center-of-mass energy of s = 4.6 GeV with the BESIII detector, four analyses of Λc+ decay are reported in the QCD 17 conference. The measurements of singly Cabibbo-suppressed decays Λc+→pπ+π− and pK+K− are performed, and the relative branching fractions with respect to the Cabibbo-favored decay Λc+→pK−π+ are given, the absolute branching fractions are also obtained for these two decays. Evidence for the singly Cabibbo-suppressed decay Λc+→pη is found with 4.2σ, and the upper limit for Λc+→pπ0is reported. The absolute branching fraction B(Λc+→Σ−π+π+π0) is determined to be (2.11±0.33±0.14)%. In addition, an improved measurement of B(Λc+→Σ−π+π+) is determined as (1.81 ± 0.17 ± 0.09)%. The branching fraction of the inclusive decay Λc+→Λ+X is measured to be B(Λc+→Λ+X)=(38.2−2.2+2.8±0.6)%.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Joan SotoAbstractWe report on a recent investigation on heavy quarkonium hybrids that goes beyond the usual Born-Oppenheimer approximation by including not only the mixing between nearby hybrid states but also the mixing with quarkonium states. We use a systematic effective field theory framework based on NRQCD together with lattice QCD inputs. Short and long distance constraints from weak coupling pNRQCD and the QCD effective string theory are also employed. We calculate the quarkonium and hybrid spectrum for charmonium and bottomonium, and estimate a number of decay widths. Most of the isospin zero XYZ resonances fit in our spectrum either as quarkonia or as hybrid states. The mixing of hybrid states with quarkonia produces enhanced spin symmetry violations, which are instrumental to understand certain decays. We also present new results on the hyperfine splittings.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): A. Palameta, J. Ho, D. Harnett, T.G. SteeleAbstractWe use QCD Laplace sum-rules to explore mixing between conventional mesons and hybrids in the heavy quarkonium vector JPC=1−− channel. Our cross-correlator includes perturbation theory and contributions proportional to the four-dimensional and six-dimensional gluon condensates. We input experimentally determined charmonium and bottomonium hadron masses into both single and multi-resonance models in order to test them for conventional meson and hybrid components. In the charmonium sector we find evidence for meson-hybrid mixing in the J/ψ and a ≈ 4.3 GeV resonance. In the bottomonium sector, we find that the ϒ(1S), ϒ(2S), ϒ(3S), and ϒ(4S) all exhibit mixing.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): J. Ho, D. Harnett, T.G. SteeleAbstractWe present QCD Laplace sum-rule predictions of ground state masses of heavy-light open-flavour hybrid mesons. Having computed leading-order diagonal correlation functions, including up to dimension six gluon condensate contributions, we extract hybrid mass predictions for all JP∈{0±,1±}, and explore possible mixing effects with conventional meson states. Similarities are found in the mass hierarchy in both charm and bottom systems with some exceptions that are discussed.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): H. Dag, A. TurkanAbstractIn this work, we studied the radial excitations of X(4140) and like states within QCD sum rules. We chose three molecular and three diquark-antidiquark currents with the quark content cc‾ss‾ and JPC = 0++, 1++, 2++, and estimated the masses and the meson coupling constants of the first excited states coupling to these currents in the framework of QCD sum rules. The ground states coupling to these currents were analyzed in a previous work and we have shown that all of these ground states have degenerate masses within 10 MeV neighborhood of exotic meson X(4140). For the excited states, the masses are not found to be degenerate. We found that scalar and tensor currents are coupling to Ds⁎D‾s⁎ threshold. However for the axial vector currents, the first excited states found to have mass compatible with X(4274), which was measured in the same decay with X(4140). Thus we conclude that X(4274) could be a radial excitation of X(4140).

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Bin Wang, BESIII CollaborationAbstractThe BESIII experiment has collected about 6 fb-1 luminosity data samples above 3.8 GeV. Recent result on the charmonium(-like) states (or called XYZ states) from BESIII experiment is presented in this talk, including the production and decay of the X(3872) states, the vector Y states, as well as the charged and neutral charmoniumlike Zc states.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): S. BethkeAbstractThe strong coupling constant αs(MZ) is determined using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Individual values of αs(MZ) are extracted from measurements of different experiments at several centre-of-mass energies, using QCD predictions complete in NNLO perturbation theory, supplemented with NNLL approximations to all orders, and suitable sets of parton distribution functions. These values are then combined using a likelyhood-based approach, with special emphasis on a consistent treatment of systemtic uncertainties and their correlations. The final combined result is αs(MZ)=0.1177−0.0036+0.0034.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Matteo Negrini, ATLAS CollaborationAbstractHighlights on recent measurements of top quark properties in ATLAS, using pp collision data at s = 8 TeV and 13 TeV, are presented. The measurements of the top quark polarization and spin correlation coefficients, the W boson helicity fractions, the structure of the Wtb vertex, the associated production of a tt‾ pair with a vector boson or a photon, and the top quark mass are all in agreement with the Standard Model expectations.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): A.D. Morton, CMS CollaborationAbstractResults of several single top physics measurements that the CMS Collaboration has produced in proton-proton collisions at the LHC at centre-of-mass energies of 7, 8 and 13 TeV, are presented. Separate investigations of the inclusive, fiducial, and differential cross section measurements in the t-channel, the production of top via the s-channel, and the measurements of standard model parameters and rare processes involving a top quark are discussed.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): L. Massa, ATLAS collaborationAbstractMeasurements of the inclusive and differential cross-sections for top-quark pair and single top production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented at centre-of-mass energies of 8 TeV and 13 TeV.The inclusive measurements reach high precision and are compared to the best available theoretical calculations. These measurements, including results using boosted tops, probe our understanding of top-pair production in the TeV regime. The results are compared to Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations.For the t-channel single top measurement, the single top-quark and anti-top-quark total production cross-sections, their ratio, as well as differential cross sections are also presented. A measurement of the production cross section of a single top quark in association with a W boson, the second largest single-top production mode, is also presented. Finally, measurements of the properties of the Wtb vertex allow to set limits on anomalous couplings. All measurements are compared to state-of-the-art theoretical calculations.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Andrew Foster, ATLAS CollaborationAbstractRecent results in the soft QCD sector of the Standard Model are presented. Measurements of low energy observables were performed with the ATLAS detector at the Large Hadron Collider at CERN. In particular, underlying event, charged particle correlation and diffraction observables are reported and various models of Monte Carlo predictions are compared to the data.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Julien Hamon, ALICE CollaborationAbstractIn this paper, an overview of recent D0, D+ and D*+ measurements, performed by ALICE in proton–proton collisions at s = 2.76, 5, 7, 8 and 13 TeV, is reported. The minimum-bias production cross sections, as well as their energy and species dependences, are compared to perturbative QCD calculations. The evolution of the D-meson yields with the event multiplicity is compared to phenomenological models.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): A. Mirjalili, A. Jamali, M. Khellat, M. AkramiAbstractWe discuss the possibility of obtaining mass and scale dependent kernels for the DGLAP evolution equations within the momentum space subtraction (MOM) class of renormalization schemes. Such well-behaved kernels would be necessary to evolve quark densities from zero at an initial scale to higher energy scales. However, in the light-front formulation of quark density operators, we are first required to carefully extract the renormalization procedures and develop a consistent definition of renormalization factors for the MOM scheme. As a result, we are led to some conditions for the implementation of MOM class of schemes for the quark densities in the context of parton model.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Günter Grindhammer, H1 and ZEUS CollaborationsAbstractRecent results on the combination of open charm and beauty production data in deep-inelastic scattering and their mparison to perturbative QCD calculations at next-to-leading order and approximate next-to-next-to-leading order are presented. The combined data are used to extract the masses of the charm and beauty quarks at next-to-leading order. Inclusive jet and dijet cross sections in deep-inelastic scattering are used to extract the strong coupling αs(mZ) at next-to-next-to-leading order for the first time. Finally, further new observables measured for the description of prompt photons plus jet production in deep-inelastic scattering and their comparison to perturbative QCD calculations are shown.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Andrii VerbytskyiAbstractWe study jet production in e+e− annihilation to hadrons with data recorded by the OPAL experiment at LEP at centre-of-mass energies between 91 GeV and 209 GeV. The jet production rates were measured with Durham and for the first time with the anti-kt and SISCone jet clustering algorithms. We compare the data with predictions by modern Monte Carlo event generators.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Rajat Gupta, CMS CollaborationAbstractRecent results on the double parton scattering studies and measurement of the underlying event activity, performed using proton-proton collisions data collected using the CMS detector are presented. Comparisons to previous results at different center of mass energies are also reported.

Abstract: Publication date: January–March 2018Source: Nuclear and Particle Physics Proceedings, Volumes 294–296Author(s): Sebastien Prince, ATLAS CollaborationAbstractThe production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the proton structure. The production of prompt photons in association with jets provides an additional testing ground for perturbative QCD with a hard colourless probe less affected by hadronisation effects than jet production. At the LHC, the ATLAS collaboration has performed precise measurements of the inclusive production of isolated prompt photons at a centre-of-mass energy of 13 TeV. The dynamics of isolated-photon plus jet production in pp collisions at a centre-of-mass energy of 8 TeV have also been measured. In addition, the integrated and differential cross sections for isolated photon pairs at a centre-of-mass energy of 8 TeV have been measured. The results are compared with state-of-the art theory predictions at next-to-leading order in perturbative QCD.