We present an inclusive search for anomalous production of single-photon events from neutrino interactions in the MicroBooNE experiment. The search and its signal definition are motivated by the previous observation of a low-energy excess of electromagnetic shower events from the MiniBooNE experiment. We use the Wire-Cell reconstruction framework to select a sample of inclusive single-photon final-state interactions with a final efficiency and purity of 7.0% and 40.2%, respectively. We leverage simultaneous measurements of sidebands of charged current <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub></math> interactions and neutral current interactions producing <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>π</mi><mn>0</mn></msup></math> mesons to constrain signal and background predictions and reduce uncertainties. We perform a blind analysis using a dataset collected from February 2016 to July 2018, corresponding to an exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>6.34</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>20</mn></mrow></msup></mrow></math> protons on target from the Booster Neutrino Beam at Fermilab. In the full signal region, we observe agreement between the data and the prediction, with a goodness-of-fit <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math> value of 0.11. We then isolate a subsample of these events containing no visible protons, and observe <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>93</mn><mo>±</mo><mn>22</mn><mrow><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>35</mn><mrow><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo></mrow></mrow></math> data events above prediction, corresponding to just above <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>σ</mi></math> local significance, concentrated at shower energies below 600 MeV.

United States

P. Abratenko

D. Andrade Aldana

United Kingdom

L. Arellano

J. Asaadi

Israel

A. Ashkenazi

S. Balasubramanian

B. Baller

A. Barnard

G. Barr

D. Barrow

J. Barrow

V. Basque

J. Bateman

O. Benevides Rodrigues

S. Berkman

A. Bhat

M. Bhattacharya

M. Bishai

A. Blake

B. Bogart

T. Bolton

M.B. Brunetti

L. Camilleri

D. Caratelli

F. Cavanna

G. Cerati

A. Chappell

Y. Chen

J.M. Conrad

M. Convery

L. Cooper-Troendle

Spain

J.I. Crespo-Anadón

R. Cross

M. Del Tutto

S.R. Dennis

P. Detje

Switzerland

R. Diurba

Z. Djurcic

K. Duffy

S. Dytman

B. Eberly

P. Englezos

A. Ereditato

J.J. Evans

C. Fang

W. Foreman

B.T. Fleming

D. Franco

A.P. Furmanski

F. Gao

D. Garcia-Gamez

S. Gardiner

G. Ge

S. Gollapinni

E. Gramellini

P. Green

H. Greenlee

L. Gu

W. Gu

R. Guenette

P. Guzowski

L. Hagaman

M.D. Handley

O. Hen

C. Hilgenberg

G.A. Horton-Smith

A. Hussain

B. Irwin

M.S. Ismail

C. James

China

X. Ji

J.H. Jo

R.A. Johnson

D. Kalra

G. Karagiorgi

W. Ketchum

M. Kirby

T. Kobilarcik

N. Lane

J.Y. Li

Y. Li

K. Lin

B.R. Littlejohn

L. Liu

W.C. Louis

X. Luo

T. Mahmud

C. Mariani

D. Marsden

J. Marshall

N. Martinez

D.A. Martinez Caicedo

S. Martynenko

A. Mastbaum

I. Mawby

N. McConkey

L. Mellet

J. Mendez

J. Micallef

A. Mogan

Inclusive Search for Anomalous Single-Photon Production in MicroBooNE

The decay of light bosonic dark matter particles can produce a bright electron/positron (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math>) flux that can be strongly constrained by local Voyager observations of the direct <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> flux, as well as 511 keV line and x-ray continuum observations of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> emission. We carefully analyze the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> yield and resulting cosmic ray and x-ray spectra from theoretically well-motivated light dark matter models, including (a) electrophilic axion-like particles, (b) dark photons, (c) scalars, and (d) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>i</mi></msub><mo>−</mo><msub><mi>L</mi><mi>j</mi></msub></math> vector bosons. We use the morphology and spectrum of the INTEGRAL 511 keV line data, the eROSITA x-ray continuum spectrum and the Voyager <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> spectrum to constrain the decay lifetime and coupling of each dark matter model. We find that 511 keV observations typically set world-leading limits on bosonic dark matter decay below masses of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><mn>1</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, while eROSITA observations provide the strongest constraints in the range from 1–10 GeV. Finally, we forecast future limits from 21 cm line searches with next-generation HERA data.

Sweden

Thong T.Q. Nguyen

Pedro De la Torre Luque

Italy

Isabelle John

Shyam Balaji

Pierluca Carenza

Germany

Tim Linden

INTEGRAL, eROSITA and Voyager constraints on light bosonic dark matter: ALPs, dark photons, scalars, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>i</mi></msub><mo>−</mo><msub><mi>L</mi><mi>j</mi></msub></math> vectors

We compute the complex, long-distance two-photon-exchange amplitude which contributes to the rare <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>K</mi><mi mathvariant="normal">L</mi></msub><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> decay from lattice QCD. We use a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>24</mn><mn>3</mn></msup><mo>×</mo><mn>64</mn></math> physical-pion-mass gauge field ensemble at an inverse lattice spacing of 1.023 GeV and a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>QED</mi></mrow><mrow><mi>∞</mi></mrow></msub></mrow></math>-based formalism. Our implementation strategies for all five non-SU(3)-flavor-suppressed diagram topologies are given in detail. We achieve a 25% statistical precision on the dispersive part of this long-distance amplitude. This calculation is carried out with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow></math> quark flavors and therefore requires the addition of counterterms to compensate for the absence of the Glashow-Iliopoulos-Maiani mechanism. These counterterms are not included in the current calculation and will be the subject of a second paper. Although a direct comparison to experiment cannot yet be made because of those omitted counterterms, the present exploratory calculation allows one to identify principal sources of statistical uncertainty in this calculation. The precision of our results is limited by the reconstruction of the physical contribution of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi></math> intermediate state, for which various strategies are tested and compared.

Peter Boyle

En-Hung Chao

Norman Christ

Ceran Hu

Luchang Jin

Yidi Zhao

Exploratory calculation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>K</mi><mi mathvariant="normal">L</mi></msub><mo stretchy="false">→</mo><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> decay from lattice QCD at physical pion mass

The short-baseline near detector (SBND), the near detector in the short-baseline neutrino program at Fermi National Accelerator Laboratory, is located just 110 m from the booster neutrino beam target. Thanks to this close proximity, relative to its <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>4</mn><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">m</mi><mo stretchy="false">×</mo><mn>4</mn><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">m</mi></mrow></math> front face, neutrinos enter SBND over a range of angles from 0° to approximately 1.6°, enabling the detector to sample variations in the neutrino flux as a function of the angle—a technique known as precision reaction-independent spectrum measurement (PRISM), referred to here as SBND-PRISM. In this paper, we show how muon- and electron-neutrino fluxes vary as a function of the neutrino beam axis angle and how this can be exploited to expand the physics potential of SBND. We make use of a model that predicts an angle-dependent electron-neutrino excess signal to illustrate this effect, such as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>μ</mi></msub><mo stretchy="false">→</mo><msub><mi>ν</mi><mi>e</mi></msub></math> oscillations. We present how SBND-PRISM provides a method to add robustness against uncertainties in cross-section modeling and, more generally, uncertainties that do not depend on the spatial position of neutrino interaction inside the detector. The fluxes, along with their associated covariance matrices, are made publicly available with this publication.

R. Acciarri

C. Adams

L. Aliaga-Soplin

O. Alterkait

R. Alvarez-Garrote

C. Andreopoulos

A. Antonakis

A. Beever

E. Belchior

M. Betancourt

D. Brailsford

A. Brandt

S. Brickner

D. Carber

B. Carlson

M.F. Carneiro

R. Castillo

H. Chen

S. Chung

M.F. Cicala

R. Coackley

C. Cuesta

Y. Dabburi

O. Dalager

M. Dall’Olio

R. Darby

Brazil

V. do Lago Pimentel

S. Dominguez-Vidales

M. Dubnowski

A. Ezeribe

C. Fan

A. Filkins

B. Fleming

G. Fricano

I. Furic

A. Furmanski

S. Gao

I. Gil-Botella

W.C. Griffith

A. Hamer

P. Hamilton

R. Harnik

A. Hergenhan

M. Hernandez-Morquecho

P. Holanda

B. Howard

Z. Imani

R.S. Jones

M. Jung

T. Junk

L. Kashur

K.J. Kelly

M. King

J. Klein

L. Kotsiopoulou

S. Kr Das

T. Kroupová

V.A. Kudryavtsev

J. Larkin

H. Lay

R. LaZur

Sampling off-axis neutrino fluxes with the short-baseline near detector

We present the strongest experimental limits to date on the mixing angle, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi></math>, with which a new scalar particle, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi></math>, mixes with the Higgs field in the mass range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>110</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi><mo>&lt;</mo><msub><mi>m</mi><mi>S</mi></msub><mo>&lt;</mo><mn>155</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>. This result uses the MicroBooNE liquid argon time projection chamber to search for decays of these Higgs-portal scalar particles through the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> channel with the decays of kaons in the NuMI neutrino beam acting as the source of the scalar particles. The analysis uses an exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2.01</mn><mo>×</mo><msup><mn>10</mn><mn>21</mn></msup></math> protons on target of NuMI beam data including periods when the beam focusing system was configured to focus positively charged hadrons and separate periods when negatively charged hadrons were focused. The analysis searches for scalar particles produced from kaons decaying in flight in the beam’s decay volume and at rest in the target and absorber. At <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>S</mi></msub><mo>=</mo><mn>125</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>S</mi></msub><mo>=</mo><mn>150</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math>) we set a limit of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi><mo>&lt;</mo><mn>3.19</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math> (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>θ</mi><mo>&lt;</mo><mn>2.79</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>4</mn></mrow></msup></math>) at the 95% confidence level.

A. Bhanderi

Y.J. Jwa

Search for the production of Higgs-portal scalar bosons in the NuMI beam using the MicroBooNE detector

A search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mrow><mi mathvariant="normal">S</mi><mo stretchy="false">(</mo><mi mathvariant="normal">L</mi><mo stretchy="false">)</mo></mrow><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> decays is performed using proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>5.4</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>. No <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>K</mi><mrow><mi mathvariant="normal">S</mi><mo stretchy="false">(</mo><mi mathvariant="normal">L</mi><mo stretchy="false">)</mo></mrow><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><msup><mi>μ</mi><mo>+</mo></msup><msup><mi>μ</mi><mo>−</mo></msup></math> signals are found and upper limits are set for the first time on the branching fractions <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mrow><mi>K</mi></mrow><mrow><mi mathvariant="normal">S</mi></mrow><mrow><mn>0</mn></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><mrow><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></mrow></mrow><mo>&lt;</mo><mn>1.4</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>9</mn></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><msubsup><mrow><mi>K</mi></mrow><mrow><mi mathvariant="normal">L</mi></mrow><mrow><mn>0</mn></mrow></msubsup><mo stretchy="false">→</mo><mrow><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><mrow><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo></mrow></mrow><mo>&lt;</mo><mn>6.6</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>7</mn></mrow></msup></mrow></math>, at the 90% confidence level.

Netherlands

R. Aaij

A.S.W. Abdelmotteleb

C. Abellan Beteta

F. Abudinén

Search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mi>K</mi></mrow><mrow><mrow><mi mathvariant="normal">S</mi><mo stretchy="false">(</mo><mi mathvariant="normal">L</mi><mo stretchy="false">)</mo></mrow></mrow><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mrow><mi>π</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>π</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>μ</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> decays at LHCb