| 1. |
- Aartsen, M. G., et al.
(författare)
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Neutrino oscillation studies with IceCube-DeepCore
- 2016
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 908, s. 161-177
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Tidskriftsartikel (refereegranskat)abstract
- IceCube, a gigaton-scale neutrino detector located at the South Pole, was primarily designed to search for astrophysical neutrinos with energies of PeV and higher. This goal has been achieved with the detection of the highest energy neutrinos to date. At the other end of the energy spectrum, the DeepCore extension lowers the energy threshold of the detector to approximately 10 GeV and opens the door for oscillation studies using atmospheric neutrinos. An analysis of the disappearance of these neutrinos has been completed, with the results produced being complementary with dedicated oscillation experiments. Following a review of the detector principle and performance, the method used to make these calculations, as well as the results, is detailed. Finally, the future prospects of IceCube-DeepCore and the next generation of neutrino experiments at the South Pole (IceCube-Gen2, specifically the PINGU sub-detector) are briefly discussed.
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| 2. |
- Abulaiti, Yiming, et al.
(författare)
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High-E-T isolated-photon plus jets production in pp collisions at root s=8 TeV with the ATLAS detector
- 2017
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 918, s. 257-316
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Tidskriftsartikel (refereegranskat)abstract
- The dynamics of isolated-photon plus one-, two- and three-jet production in pp collisions at a centre-of-mass energy of 8 TeV are studied with the ATLAS detector at the LHC using a data set with an integrated luminosity of 20.2 fb(-1). Measurements of isolated-photon plus jets cross sections are presented as functions of the photon and jet transverse momenta. The cross sections as functions of the azimuthal angle between the photon and the jets, the azimuthal angle between the jets, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass system are presented. The pattern of QCD radiation around the photon and the leading jet is investigated by measuring jet production in an annular region centred on each object; enhancements are observed around the leading jet with respect to the photon in the directions towards the beams. The experimental measurements are compared to several different theoretical calculations, and overall a good description of the data is found.
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| 3. |
- Abulaiti, Yiming, et al.
(författare)
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Measurement of D-*+/-, D-+/- and D-S(+/-) meson production cross sections in pp collisions at root s=7 TeV with the ATLAS detector
- 2016
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 907, s. 717-763
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Tidskriftsartikel (refereegranskat)abstract
- The production of D*(+/-), D-+/- and D-S(+/-) charmed mesons has been measured with the ATLAS detector in pp collisions at,/7s = 7 TeV at the LHC, using data corresponding to an integrated luminosity of 280 nb(-)1(.) The charmed mesons have been reconstructed in the range of transverse momentum 3.5 < p(T)(D) < 100 GeV and pseudorapidity vertical bar eta(D)vertical bar < 2.1. The differential cross sections as a function of transverse momentum and pseudorapidity were measured for D*(+/-) and D-+/- production. The next-to-leading-order QCD predictions are consistent with the data in the visible kinematic region within the large theoretical uncertainties. Using the visible D cross sections and an extrapolation to the full kinematic phase space, the strangeness -suppression factor in charm fragmentation, the fraction of charged non -strange D mesons produced in a vector state, and the total cross section of charm production at root s = 7 TeV were derived.
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| 4. |
- Adolphi, C., et al.
(författare)
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Exclusive omega meson muoproduction on transversely polarised protons
- 2017
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Ingår i: Nuclear Physics B. - : ELSEVIER SCIENCE BV. - 0550-3213 .- 1873-1562. ; 915, s. 454-475
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Tidskriftsartikel (refereegranskat)abstract
- Exclusive production of omega mesons was studied at the COMPASS experiment by scattering 160GeV/c muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality 1(GeV/c)(2) < Q(2) < 10(GeV/c)(2), Bjorken scaling variable 0.003 < xBj < 0.3 and transverse momentum squared of the omega meson 0.05(GeV/c)(2) < p(T)(2) < 0.5(GeV/c)(2). The measured asymmetries are sensitive to the nucleon helicity-flip Generalised Parton Distributions (GPD) Et hat are related to the orbital angular momentum of quarks, the chiral-odd GPDs H-T that are related to the transversity Parton Distribution Functions, and the sign of the pi omega transition form factor. The results are compared to recent calculations of a GPD-based model.
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| 5. |
- Anastasiou, Alexandros, et al.
(författare)
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Are all supergravity theories Yang-Mills squared?
- 2018
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Ingår i: Nuclear Physics B. - : Elsevier. - 0550-3213 .- 1873-1562. ; 934, s. 606-633
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Tidskriftsartikel (refereegranskat)abstract
- Using simple symmetry arguments we classify the ungauged D = 4, N = 2 supergravity theories, coupled to both vector and hyper multiplets through homogeneous scalar manifolds, that can be built as the product of N = 2 and N= 0 matter-coupled Yang-Mills gauge theories. This includes all such supergravities with two isolated exceptions: pure supergravity and the T-3 model.
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| 6. |
- Baussan, E., et al.
(författare)
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A very intense neutrino super beam experiment for leptonic CP violation discovery based on the European spallation source linac
- 2014
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Ingår i: Nuclear Physics B. - : Elsevier BV. - 0550-3213 .- 1873-1562. ; 885, s. 127-149
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Tidskriftsartikel (refereegranskat)abstract
- Very intense neutrino beams and large neutrino detectors will be needed in order to enable the discovery of CP violation in the leptonic sector. We propose to use the proton linac of the European Spoliation Source currently under construction in Lund, Sweden, to deliver, in parallel with the spoliation neutron production, a very intense, cost effective and high performance neutrino beam. The baseline program for the European Spoliation Source linac is that it will be fully operational at 5 MW average power by 2022, producing 2 GeV 2.86 ms long proton pulses at a rate of 14 Hz. Our proposal is to upgrade the linac to 10 MW average power and 28 Hz, producing 14 pulses/s for neutron production and 14 pulses/s for neutrino production. Furthermore, because of the high current required in the pulsed neutrino horn, the length of the pulses used for neutrino production needs to be compressed to a few mu s with the aid of an accumulator ring. A long baseline experiment using this Super Beam and a megaton underground Water Cherenkov detector located in existing mines 300-600 km from Lund will make it possible to discover leptonic CP violation at 5 sigma significance level in up to 50% of the leptonic Dirac CP-violating phase range. This experiment could also determine the neutrino mass hierarchy at a significance level of more than 3 sigma if this issue will not already have been settled by other experiments by then. The mass hierarchy performance could be increased by combining the neutrino beam results with those obtained from atmospheric neutrinos detected by the same large volume detector. This detector will also be used to measure the proton lifetime, detect cosmological neutrinos and neutrinos from supernova explosions. Results on the sensitivity to leptonic CP violation and the neutrino mass hierarchy are presented.
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| 7. |
- Bijnens, Johan, et al.
(författare)
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A new global fit of the L(i)(r) at next-to-next-to-leading order in Chiral Perturbation Theory
- 2012
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Ingår i: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 854:3, s. 631-665
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in Undeterminednew fit is done to obtain numerical values for the order p(4) low-energy-constants L(i)(r) in Chiral Perturbation Theory. This includes both new data and new calculated observables. We take into account masses, decay constants, K(l4), pi pi and pi K scattering lengths and slopes and the slope of the pion scalar formfactor. We compare in detail where the changes w.r.t. the 10 years old "fit 10" come from. We discuss several scenarios for estimating the order p(6) constants C(i)(r) and search for possible values of them that provide a good convergence for the ChPT series. We present two such sets. One big change is that the fits do not have the expected behaviour in the limit of large N(c) as well as before. (C) 2011 Elsevier B.V. All rights reserved.
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| 8. |
- Bijnens, Johan, et al.
(författare)
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Hard pion chiral perturbation theory for B -> pi and D -> pi formfactors
- 2010
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Ingår i: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 840:1-2, s. 54-66
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Tidskriftsartikel (refereegranskat)abstract
- We use one-loop Heavy Meson Chiral Perturbation Theory (HMChPT) as well as a relativistic formulation to calculate the chiral logarithms m(pi)(2) log (m(pi)(2)/mu(2)) contributing to the formfactors of the semileptonic B -> pi decays at momentum transfer q(2) away from q(max)(2) = (m(B) - m(pi))(2). We give arguments why this chiral behaviour is reliable even in the energy regime with hard or fast pions. These results can be used to extrapolate the formfactors calculated on the lattice to lower light meson masses. (C) 2010 Elsevier B.V. All rights reserved.
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| 9. |
- Bijnens, Johan, et al.
(författare)
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Leading logarithms for the nucleon mass
- 2015
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Ingår i: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 891, s. 700-719
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Tidskriftsartikel (refereegranskat)abstract
- Within the heavy baryon chiral perturbation theory approach, we have studied the leading logarithm behavior of the nucleon mass up to four-loop order exactly and we present some results up to six-loop order as well as an all-order conjecture. The same methods allow to calculate the main logarithm multiplying the terms with fractional powers of the quark mass. We calculate thus the coefficients of m(2n+1) log((n-1)) (mu(2)/m(2)) and m(2n+2) log(n) (mu(2)/m(2)) with m the lowest-order pion mass. A side result is the leading divergence for a general heavy baryon loop integral. (C) 2014 The Authors. Published by Elsevier B.V.
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| 10. |
- Bijnens, Johan, et al.
(författare)
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Leading logarithms in N-flavour mesonic Chiral Perturbation Theory
- 2013
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Ingår i: Nuclear Physics, Section B. - : Elsevier BV. - 0550-3213. ; 873:1, s. 137-164
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Tidskriftsartikel (refereegranskat)abstract
- We extend earlier work on leading logarithms in the massive nonlinear O(n) sigma model to the case of SU(N) x SU(N)/SU(N) which coincides with mesonic Chiral Perturbation Theory for N flavours of light quarks. We discuss the leading logarithms for the mass and decay constant to six loops and for the vacuum expectation value ((q) over barq) to seven loops. For dynamical quantities the expressions grow extremely large much faster such that we only quote the leading logarithms to five loops for the vector and scalar form factor and for meson-meson scattering. The last quantity we consider is the vector-vector to meson-meson amplitude where we quote results up to four loops for a subset of quantities, in particular for the pion polarizabilities. As a side result we provide an elementary proof that the factors of N appearing at each loop order are odd or even depending on the order and the remaining traces over external flavours. (C) 2013 Published by Elsevier B.V.
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