Wed·Jun 24, 2020Wednesday·June 24, 2020

1. 01*

   COHERENT Collaboration data release from the first detection of coherent elastic neutrino-nucleus scattering on argon

   COHERENT Collaboration: D. Akimov🇷🇺 · J.B. Albert🇺🇸 · P. An🇺🇸 · C. Awe🇺🇸 · P.S. Barbeau🇺🇸 · B. Becker🇺🇸 · V. Belov🇷🇺 · M.A. Blackston🇺🇸 · L. Blokland🇺🇸 · A. Bolozdynya🇷🇺 · B. Cabrera-Palmer🇺🇸 · N. Chen🇺🇸 and 70 other authors

   Release of COHERENT collaboration data from the first detection of coherent elastic neutrino-nucleus scattering (CEvNS) on argon. This release corresponds with the results of "Analysis A" published in Akimov et al., arXiv:2003.10630 [nucl-ex]. Data is shared in a binned, text-based format representing both "signal" and "backgrounds" along with associated uncertainties such that the included data can be used to perform independent analyses. This document describes the contents of the data release as well as guidance on the use of the data. Included example code in C++ (ROOT) and Python show one possible use of the included data.

   nucl-exhep-ex81 citations
2. 02*

   Two-photon exchange from intermediate state resonances in elastic electron-proton scattering

   Jaseer Ahmed🇨🇦 · P. G. Blunden🇨🇦 · W. Melnitchouk🇺🇸

   We use a recently developed dispersive approach to compute the two-photon exchange (TPE) correction to elastic electron-proton scattering, including contributions from hadronic $J^P=1/2^{\pm }$ and $3/2^{\pm }$ resonant intermediate states below~1.8~GeV. For the transition amplitudes from the proton ground state to the resonant excited states we employ new exclusive meson electroproduction data from CLAS at $Q^2\lesssim 5$~GeV${}^2$, and we explore the effects of both fixed and dynamic widths for the resonances. Among the resonant states, the $N(1520)3/2^{-}$ becomes dominant for $Q^2\gtrsim 2$~GeV${}^2$, with a sign opposite to the comparably sized $\Delta (1232)3/2^{+}$ contribution, leading to an overall increase in the size of the TPE correction to the cross section relative to the nucleon only contribution at higher $Q^2$ values. The results are in good overall agreement with recent $e^{+}p$ to $e^{-}p$ cross section ratio and polarization transfer measurements, and provide compelling evidence for a resolution of the electric to magnetic form factor ratio discrepancy.

   ↳ nucl-thhep-phnucl-exPRC(2020)·34 citations
3. 03*

   A Somewhat Random Walk Through Nuclear and Particle Physics

   Thomas D. Cohen🇺🇸 · Nicholas R. Poniatowski🇺🇸

   These notes are an outgrowth of an advanced undergraduate course taught at the University of Maryland, College Park. They are intended as an introduction to various aspects of particle and nuclear physics with an emphasis on the role of symmetry. The basic philosophy is to introduce many of the fundamental ideas in nuclear and particle physics using relatively sophisticated mathematical tools -- but to do so in as a simplified a context to explain the underlying ideas. Thus, for example, the Higgs mechanism is discussed in terms of an Abelian Higgs model. The emphasis is largely, but not entirely theoretical in orientation. The goal is for readers to develop an understanding of many of the underlying issues in a relatively sophisticated way.

   ↳ hep-phhep-exnucl-exnucl-thSciPost Phys.Lect.Notes(2021)·0 citations
4. 04*

   Heavy-flavour correlations and jets with ALICE at the LHC

   Antonio Carlos Oliveira da Silva (for the ALICE Collaboration)🇺🇸

   This contribution summarises the results on heavy-flavour correlations and jets measured with ALICE detector. Studies of D${}^0$-tagged jets are presented in various collision systems and energies. The measurement of the fraction of jet momentum carried by the D${}^0$ meson in the direction of the jet axis ($z_{||}^{\mathrm{ch},\mathrm{jet}}$) in pp collisions at $\sqrt{s}$ = 5.02 and 13 TeV as well as the nuclear modification factor in p--Pb and Pb--Pb collisions are presented. The measurements of the production of jets tagged by electrons from heavy-flavour decays in pp and p--Pb are compared to expectations from POWHEG+PYTHIA8 simulations. The $p_{\mathrm{T}}$-differential cross section of b-tagged jets in p--Pb collisions is also reported and compared to expectations from POWHEG event generator. The azimuthal correlation of D mesons with charged particles in pp and p--Pb collisions are also presented.

   ↳ hep-exnucl-exJ.Phys.Conf.Ser.(2020)·0 citations
5. 05*

   Isobar correlations bearing information on the properties of hot disassembling nuclear sources

   S.R. Souza🇧🇷 · R. Donangelo🇧🇷

   Two-particle correlations based on the multiplicity of selected isobars are found to be sensitive to the parameterization of the fragments' binding energies and the breakup volume assumed in the model calculations. The properties of these correlations have been examined in the framework of the Statistical Multifragmentation Model as a function of the breakup temperature. The model calculations suggest that the maxima of these correlation functions occur at well separated temperatures as the breakup volumes used in the model vary from 3 to 6 times that at normal density. These volumes are within the range assumed in most statistical calculations and supported by experiments. Besides their position, the height and width of the maxima are also found to be sensitive to the parameterization of the fragments' binding energy. The magnitude of all these effects also depends on the isobars considered in the correlations. We found that, due to an interplay between the symmetry energy and the volume dependent terms of the Helmholtz free energy, in the case of nearly symmetric sources, correlations involving light mirror nuclei seem to enhance these effects. We suggest that the proposed correlation functions could be used to extract information on the fragments' energies and on the breakup volume of nuclear sources.

   ↳ nucl-thnucl-exPRC(2020)·2 citations
6. 06*

   Note on arXiv:2005.05301, 'Preparation of the Neutrino-4 experiment on search for sterile neutrino and the obtained results of measurements'

   H. Almazán🇩🇪 · M. Andriamirado🇺🇸 · A. B. Balantekin🇺🇸 · H. R. Band🇺🇸 · C. D. Bass🇺🇸 · D. E. Bergeron🇺🇸 · D. Berish🇺🇸 · A. Bonhomme🇩🇪 · N. S. Bowden🇺🇸 · J. P. Brodsky🇺🇸 · C. D. Bryan🇺🇸 · C. Buck🇩🇪 and 70 other authors

   We comment on the claimed observation [arXiv:arXiv:2005.05301] of sterile neutrino oscillations by the Neutrino-4 collaboration. Such a claim, which requires the existence of a new fundamental particle, demands a level of rigor commensurate with its impact. The burden lies with the Neutrino-4 collaboration to provide the information necessary to prove the validity of their claim to the community. In this note, we describe aspects of both the data and analysis method that might lead to an oscillation signature arising from a null experiment and describe additional information needed from the Neutrino-4 collaboration to support the oscillation claim. Additionally, as opposed to the assertion made by the Neutrino-4 collaboration, we also show that the method of 'coherent summation' using the $L/E$ parameter produces similar results to the methods used by the PROSPECT and the STEREO collaborations.

   ↳ hep-exnucl-ex36 citations
7. 07*

   $\alpha$-event Characterization and Rejection in Point-Contact HPGe Detectors

   The MAJORANA Collaboration · I.J. Arnquist🇺🇸 · F.T. Avignone III🇺🇸 · A.S. Barabash🇷🇺 · C.J. Barton🇺🇸 · F.E. Bertrand🇺🇸 · E. Blalock🇺🇸 · B. Bos🇺🇸 · M. Busch🇺🇸 · M. Buuck🇺🇸 · T.S. Caldwell🇺🇸 · Y-D. Chan🇺🇸 and 53 other authors

   P-type point contact (PPC) HPGe detectors are a leading technology for rare event searches due to their excellent energy resolution, low thresholds, and multi-site event rejection capabilities. We have characterized a PPC detector's response to $\alpha$ particles incident on the sensitive passivated and p+ surfaces, a previously poorly-understood source of background. The detector studied is identical to those in the MAJORANA DEMONSTRATOR experiment, a search for neutrinoless double-beta decay ($0\nu \beta \beta$) in ${}^{76}$Ge. $\alpha$ decays on most of the passivated surface exhibit significant energy loss due to charge trapping, with waveforms exhibiting a delayed charge recovery (DCR) signature caused by the slow collection of a fraction of the trapped charge. The DCR is found to be complementary to existing methods of $\alpha$ identification, reliably identifying $\alpha$ background events on the passivated surface of the detector. We demonstrate effective rejection of all surface $\alpha$ events (to within statistical uncertainty) with a loss of only 0.2% of bulk events by combining the DCR discriminator with previously-used methods. The DCR discriminator has been used to reduce the background rate in the $0\nu \beta \beta$ region of interest window by an order of magnitude in the MAJORANA DEMONSTRATOR, and will be used in the upcoming LEGEND-200 experiment.

   ↳ physics.ins-dethep-exnucl-exEPJC(2022)·38 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.