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Author |
Khachatryan, M. et al, Coloma, P. |
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Title |
Electron-beam energy reconstruction for neutrino oscillation measurements |
Type |
Journal Article |
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Year |
2021 |
Publication |
Nature |
Abbreviated Journal |
Nature |
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Volume |
599 |
Issue |
7886 |
Pages |
565-570 |
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Keywords |
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Abstract |
Neutrinos exist in one of three types or 'flavours'-electron, muon and tau neutrinos-and oscillate from one flavour to another when propagating through space. This phenomena is one of the few that cannot be described using the standard model of particle physics (reviewed in ref. (1)), and so its experimental study can provide new insight into the nature of our Universe (reviewed in ref. (2)). Neutrinos oscillate as a function of their propagation distance (L) divided by their energy (E). Therefore, experiments extract oscillation parameters by measuring their energy distribution at different locations. As accelerator-based oscillation experiments cannot directly measure E, the interpretation of these experiments relies heavily on phenomenological models of neutrino-nucleus interactions to infer E. Here we exploit the similarity of electron-nucleus and neutrino-nucleus interactions, and use electron scattering data with known beam energies to test energy reconstruction methods and interaction models. We find that even in simple interactions where no pions are detected, only a small fraction of events reconstruct to the correct incident energy. More importantly, widely used interaction models reproduce the reconstructed energy distribution only qualitatively and the quality of the reproduction varies strongly with beam energy. This shows both the need and the pathway to improve current models to meet the requirements of next-generation, high-precision experiments such as Hyper-Kamiokande (Japan)(3) and DUNE (USA)(4). Electron scattering measurements are shown to reproduce only qualitatively state-of-the-art lepton-nucleus energy reconstruction models, indicating that improvements to these particle-interaction models are required to ensure the accuracy of future high-precision neutrino oscillation experiments. |
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Address  |
[Khachatryan, M.; Hauenstein, F.; Weinstein, L. B.] Old Domin Univ, Norfolk, VA USA, Email: adishka@mit.edu |
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Publisher |
Nature Portfolio |
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Language |
English |
Summary Language |
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Original Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0028-0836 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000722366200013 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5073 |
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Author |
Khosa, C.K.; Sanz, V.; Soughton, M. |
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Title |
Using machine learning to disentangle LHC signatures of Dark Matter candidates |
Type |
Journal Article |
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Year |
2021 |
Publication |
Scipost Physics |
Abbreviated Journal |
SciPost Phys. |
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Volume |
10 |
Issue |
6 |
Pages |
151 - 26pp |
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Keywords |
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Abstract |
We study the prospects of characterising Dark Matter at colliders using Machine Learning (ML) techniques. We focus on the monojet and missing transverse energy (MET) channel and propose a set of benchmark models for the study: a typical WIMP Dark Matter candidate in the form of a SUSY neutralino, a pseudo-Goldstone impostor in the shape of an Axion-Like Particle, and a light Dark Matter impostor whose interactions are mediated by a heavy particle. All these benchmarks are tensioned against each other, and against the main SM background (Z+jets). Our analysis uses both the leading-order kinematic features as well as the information of an additional hard jet. We explore different representations of the data, from a simple event data sample with values of kinematic variables fed into a Logistic Regression algorithm or a Fully Connected Neural Network, to a transformation of the data into images related to probability distributions, fed to Deep and Convolutional Neural Networks. We also study the robustness of our method against including detector effects, dropping kinematic variables, or changing the number of events per image. In the case of signals with more combinatorial possibilities (events with more than one hard jet), the most crucial data features are selected by performing a Principal Component Analysis. We compare the performance of all these methods, and find that using the 2D images of the combined information of multiple events significantly improves the discrimination performance. |
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Address |
[Khosa, Charanjit Kaur; Sanz, Veronica; Soughton, Michael] Univ Sussex, Dept Phys & Astron, Brighton BN1 9QH, E Sussex, England, Email: Charanjit.Kaur@sussex.ac.uk; |
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Corporate Author |
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Thesis |
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Publisher |
Scipost Foundation |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2542-4653 |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000680038800002 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4927 |
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Author |
Kirpichnikov, D.V.; Sieber, H.; Molina Bueno, L.; Crivelli, P.; Kirsanov, M.M. |
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Title |
Probing hidden sectors with a muon beam: Total and differential cross sections for vector boson production in muon bremsstrahlung |
Type |
Journal Article |
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Year |
2021 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
104 |
Issue |
7 |
Pages |
076012 - 13pp |
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Keywords |
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Abstract |
Vector bosons, such as dark photon A' or Z', can couple to muons and be produced in the bremsstrahlung reaction mu(-) + N -> mu(-) + N + A'(Z'). Their possible subsequent invisible decay can be detected in fixed target experiments through missing energy/momentum signature. In such experiments, not only is the energy transfer to A'(Z') important but also the recoil muon angle psi μ0. In this paper, we derive the total and the double differential cross sections involved in this process using the phase space Weizsacker-Williams and improved Weizsacker-Williams approximations, as well as using exact-tree-level calculations. As an example, we compare the derived cross sections and resulting signal yields in the NA64 μexperiment that uses a 160 GeV muon beam at the CERN Super Proton Synchrotron accelerator. We also discuss its impact on the NA64 μexpected sensitivity to explore the (g – 2)(mu) anomaly favored region with a Z' boson considering 10(12) muons accumulated on target. |
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Address |
[Kirpichnikov, D., V; Kirsanov, M. M.] Inst Nucl Res, Moscow 117312, Russia, Email: kirpich@ms2.inr.ac.ru; |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2470-0010 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000707478200010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5008 |
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Author |
Kuhn, K. et al; Nacher, E. |
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Title |
Experimental study of the nature of the 1(-) and 2(-) excited excited states in Be-10 using the Be-11(p, d) reaction in inverse kinematics |
Type |
Journal Article |
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Year |
2021 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
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Volume |
104 |
Issue |
4 |
Pages |
044601 - 10pp |
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Keywords |
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Abstract |
The nature of the 1(-) and 2(-) excited states in Be-10 is studied using the Be-11(p, d) transfer reaction in inverse kinematics at 10A MeV at TRIUMF ISAC-II, in particular to assess whether either of them can be considered as an excited halo state. The angular distributions for both states are extracted using deuteron-gamma( )coincidences and analyzed using a transfer model taking into account one-step and two-step processes. A good fit of the angular distributions is obtained considering only the one-step process, whereby an inner p(3/2) neutron of Be-11 is removed, leaving the halo neutron intact. Higher-order processes however cannot be rejected. The small spectroscopic factors extracted suggest that the structure of both states is not uniquely halo-like, but rather display a more complex configuration mixing cluster and halo structures. Further insights are limited, as this experiment specifically probed the halo-like (but not cluster-like) Be-11 (1/2(+)) circle times (nu p(3/2))(-1) configuration in both states. |
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Address |
[Kuhn, K.; Sarazin, F.; Braid, R.; Hager, U.; Ilyushkin, S., V; O'Malley, P. D.; Smalley, D.] Colorado Sch Mines, Phys Dept, Golden, CO 80401 USA, Email: fsarazin@mines.edu |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9985 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000704586000001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
4995 |
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Author |
Belle II Collaboration (Abudinen, F. et al); Marinas, C. |
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Title |
Search for B+ -> K+nu(nu)over-bar Decays Using an Inclusive Tagging Method at Belle H |
Type |
Journal Article |
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Year |
2021 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
127 |
Issue |
18 |
Pages |
181802 - 10pp |
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Keywords |
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Abstract |
A search for the flavor-changing neutral-current decay B+ -> K+nu(nu) over bar is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63 fb(-1) collected at the Upsilon(4S) resonance and a sample of 9 fb(-1) collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B+ -> K+nu(nu) over bar decay, but also the inclusive properties of the other B meson in the Upsilon(4S) -> B (B) over bar event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B+ -> K+nu(nu) over bar of 4.1 x 10(-5) is set at the 90% confidence level. |
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Address |
[Lautenbach, K.; Polat, G.; Serrano, J.; Zani, L.] Aix Marseille Univ, CPPM, CNRS IN2P3, F-13288 Marseille, France |
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Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000712526000010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
5020 |
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