<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mrow><mi>JSNS</mi></mrow><mn>2</mn></msup></math> (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment searching for sterile neutrinos through the observation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>μ</mi></msub><mo stretchy="false">→</mo><msub><mover accent="true"><mi>ν</mi><mo stretchy="false">¯</mo></mover><mi>e</mi></msub></math> appearance oscillations, using neutrinos produced by muon decay-at-rest. A key aspect of the experiment involves accurately understanding the neutrino flux and the quantities of pions and muons, which are progenitors of (anti)neutrinos, given that their production rates have yet to be measured. We present the first electron-neutrino flux measurement using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi mathvariant="normal">C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts><mo stretchy="false">(</mo><msub><mrow><mi>ν</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mo stretchy="false">)</mo></mrow><mrow><mn>12</mn></mrow></msup><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mi mathvariant="normal">g</mi><mo>.</mo><mi mathvariant="normal">s</mi><mo>.</mo></mrow></msub></mrow></math> reaction in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>, yielding a flux of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>6.7</mn><mo>±</mo><mn>1.6</mn><mo stretchy="false">(</mo><mi>stat</mi><mo stretchy="false">)</mo><mo>±</mo><mn>1.7</mn><mo stretchy="false">(</mo><mi>syst</mi><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>9</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mtext> </mtext><msup><mrow><mi>proton</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> at the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> detector location, located at 24 meters distance from the mercury target. This flux measurement is consistent with predictions from simulations based on hadron models.

Japan

T. Dodo

South Korea

M.K. Cheoun

J.H. Choi

J.Y. Choi

J. Goh

K. Haga

M. Harada

S. Hasegawa

W. Hwang

H.I. Jang

J.S. Jang

K.K. Joo

D.E. Jung

S.K. Kang

Y. Kasugai

T. Kawasaki

E.M. Kim

E.J. Kim

S.Y. Kim

China

S.B. Kim

H. Kinoshita

T. Konno

D.H. Lee

United States

C. Little

T. Maruyama

E. Marzec

S. Masuda

S. Meigo

D.H. Moon

T. Nakano

M. Niiyama

K. Nishikawa

M.Y. Pac

B.J. Park

H.W. Park

J.B. Park

J.S. Park

R.G. Park

United Kingdom

S.J.M. Peeters

J.W. Ryu

K. Sakai

S. Sakamoto

T. Shima

C.D. Shin

J. Spitz

F. Suekane

Y. Sugaya

K. Suzuya

Y. Yamaguchi

I.S. Yeo

I. Yu

First <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>JSNS</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> measurement of the electron neutrino flux using the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mrow><mmultiscripts><mrow><mi mathvariant="normal">C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts></mrow><mo stretchy="false">(</mo><msub><mrow><mi>ν</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">)</mo><mmultiscripts><mrow><msub><mrow><mi mathvariant="normal">N</mi></mrow><mrow><mi mathvariant="normal">g</mi><mo>.</mo><mi mathvariant="normal">s</mi><mo>.</mo></mrow></msub></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts></mrow></math> reaction

We measure the spin-density matrix elements (SDMEs) for the photoproduction of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mo>(</mo><mn>1020</mn><mo>)</mo></mrow></math> off of the proton in its decay to <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>L</mi><mn>0</mn></msubsup></mrow></math>, using 105 <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>pb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> of data collected with a linearly polarized photon beam using the GlueX experiment. The SDMEs are measured in nine bins of the squared four-momentum transfer <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>t</mi></math> in the range <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>−</mo><mi>t</mi><mo>=</mo><mn>0.15</mn><mo>−</mo><mn>1.0</mn></mrow></math> <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mrow><mi>GeV</mi></mrow><mn>2</mn></msup></math>, providing the first measurement of their <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>t</mi></math> dependence for photon beam energies of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>E</mi><mi>γ</mi></msub><mo>=</mo><mn>8.2</mn><mo>−</mo><mn>8.8</mn></mrow></math> GeV. We confirm the dominance of Pomeron exchange in this region and put constraints on the contribution of other Regge exchanges. We also find that helicity amplitudes where the helicity of the photon and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mo>(</mo><mn>1020</mn><mo>)</mo></mrow></math> differ by two units are negligible.

Germany

F. Afzal

C.S. Akondi

M. Albrecht

M. Amaryan

S. Arrigo

V. Arroyave

A. Asaturyan

A. Austregesilo

Z. Baldwin

F. Barbosa

J. Barlow

E. Barriga

R. Barsotti

D. Barton

V. Baturin

V.V. Berdnikov

T. Black

W. Boeglin

M. Boer

W.J. Briscoe

T. Britton

R. Brunner

S. Cao

E. Chudakov

G. Chung

P.L. Cole

O. Cortes

V. Crede

M.M. Dalton

D. Darulis

A. Deur

S. Dobbs

Russia

A. Dolgolenko

M. Dugger

R. Dzhygadlo

D. Ebersole

M. Edo

H. Egiyan

T. Erbora

P. Eugenio

A. Fabrizi

C. Fanelli

S. Fang

A.M. Foda

M. Fritsch

S. Furletov

L. Gan

H. Gao

A. Gardner

A. Gasparian

D.I. Glazier

C. Gleason

V.S. Goryachev

B. Grube

J. Guo

L. Guo

J. Hernandez

K. Hernandez

N.D. Hoffman

Canada

D. Hornidge

Chile

G. Huber

P. Hurck

W. Imoehl

D.G. Ireland

M.M. Ito

I. Jaegle

N.S. Jarvis

T. Jeske

M. Jing

R.T. Jones

Armenia

V. Kakoyan

G. Kalicy

V. Khachatryan

Greece

C. Kourkoumelis

A. LaDuke

I. Larin

D. Lawrence

D.I. Lersch

H. Li

B. Liu

K. Livingston

L. Lorenti

V. Lyubovitskij

A. Mahmood

H. Marukyan

V. Matveev

M. McCaughan

M. McCracken

C.A. Meyer

R. Miskimen

R.E. Mitchell

K. Mizutani

P. Moran

V. Neelamana

L. Ng

E. Nissen

S. Orešić

A.I. Ostrovidov

Z. Papandreou

C. Paudel

Measurement of spin-density matrix elements in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mrow><mo>(</mo><mn>1020</mn><mo>)</mo></mrow><mo>→</mo><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup><msubsup><mi>K</mi><mi>L</mi><mn>0</mn></msubsup></mrow></math> photoproduction with a linearly polarized photon beam at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>E</mi><mi>γ</mi></msub><mo>=</mo><mn>8.2</mn><mo>–</mo><mn>8.8</mn><mo> </mo><mi>GeV</mi></mrow></math>

This Letter presents an investigation of low-energy electron-neutrino interactions in the Fermilab Booster Neutrino Beam by the MicroBooNE experiment, motivated by the excess of electron-neutrino-like events observed by the MiniBooNE experiment. This is the first measurement to use data from all five years of operation of the MicroBooNE experiment, corresponding to an exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1.11</mn><mo>×</mo><msup><mn>10</mn><mn>21</mn></msup></math> protons on target, a 70% increase on past results. Two samples of electron neutrino interactions without visible pions are used, one with visible protons and one without any visible protons. The MicroBooNE data show reasonable agreement with the nominal prediction, with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi></math> values <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≥</mo><mn>26.7</mn><mo>%</mo></math> when the two <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math> samples are combined, though the prediction exceeds the data in limited regions of phase space. The data are further compared to two empirical models that modify the predicted rate of electron-neutrino interactions in different variables in the simulation to match the unfolded MiniBooNE low energy excess. In the first model, this unfolding is performed as a function of electron neutrino energy, while the second model aims to match the observed shower energy and angle distributions of the MiniBooNE excess. This measurement excludes an electronlike interpretation of the MiniBooNE excess based on these models at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo>&gt;</mo><mn>99</mn><mo>%</mo><mtext> </mtext><mtext> </mtext><msub><mrow><mi>CL</mi></mrow><mrow><mi mathvariant="normal">s</mi></mrow></msub></mrow></math> in all kinematic variables.

P. Abratenko

D. Andrade Aldana

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

Search for an Anomalous Production of Charged-Current <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>ν</mi><mi>e</mi></msub></math> Interactions without Visible Pions across Multiple Kinematic Observables in MicroBooNE