We propose a novel method to probe gluon linear polarization via energy correlations in hard scattering processes. This approach exploits the characteristic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>cos</mi><mn>2</mn><mi>ϕ</mi></math> azimuthal modulation in single- and two-point energy correlations within jets initiated by polarized gluons. In contrast to conventional techniques that rely on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>k</mi><mi>t</mi></msub></math> resummation or intricate jet substructure observables, our method offers a theoretically robust and experimentally accessible avenue for gluon polarimetry. We perform an all-order analysis within the Ciafaloni-Catani-Fiorani-Marchesini formalism, incorporating coherent branching effects to achieve improved precision. Our predictions can be tested at current and future facilities, including the LHC, RHIC, HERA, and the EIC.

Yu-Kun Song

Shu-Yi Wei

Lei Yang

Jian Zhou

Gluon Polarimetry with Energy-Energy Correlators

In recent neutrino detectors, neutrons produced in neutrino reactions play an important role. Muon capture on oxygen nuclei is one of the processes that produce neutrons in water Cherenkov detectors. We measured neutron multiplicity in the process using cosmic ray muons that stop in the gadolinium-loaded Super-Kamiokande detector. For this measurement, neutron detection efficiency is obtained with the muon capture events followed by gamma rays to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mn>50.2</mn><mrow><mo>−</mo><mn>2.1</mn></mrow><mrow><mo>+</mo><mn>2.0</mn></mrow></msubsup><mo>%</mo></math>. By fitting the observed multiplicity considering the detection efficiency, we measure neutron multiplicity in muon capture as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>P</mi><mo stretchy="false">(</mo><mn>0</mn><mo stretchy="false">)</mo><mo>=</mo><mn>24</mn><mo>±</mo><mn>3</mn><mo>%</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo><mo>=</mo><mn>7</mn><msubsup><mn>0</mn><mrow><mo>−</mo><mn>2</mn></mrow><mrow><mo>+</mo><mn>3</mn></mrow></msubsup><mo>%</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mn>6.1</mn><mo>±</mo><mn>0.5</mn><mo>%</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo><mo>=</mo><mn>0.38</mn><mo>±</mo><mn>0.09</mn><mo>%</mo></math>. This is the first measurement of the multiplicity of neutrons associated with muon capture on oxygen without neutron energy threshold.

S. Miki

K. Abe

S. Abe

Y. Asaoka

C. Bronner

M. Harada

Y. Hayato

K. Hiraide

K. Hosokawa

K. Ieki

M. Ikeda

J. Kameda

Y. Kanemura

R. Kaneshima

Y. Kashiwagi

Y. Kataoka

S. Mine

M. Miura

S. Moriyama

M. Nakahata

S. Nakayama

Y. Noguchi

K. Okamoto

G. Pronost

K. Sato

H. Sekiya

H. Shiba

K. Shimizu

M. Shiozawa

Y. Sonoda

Y. Suzuki

A. Takeda

Y. Takemoto

A. Takenaka

H. Tanaka

S. Watanabe

T. Yano

T. Kajita

K. Okumura

T. Tashiro

T. Tomiya

X. Wang

S. Yoshida

G.D. Megias

P. Fernandez

L. Labarga

N. Ospina

B. Zaldivar

B.W. Pointon

C. Yanagisawa

E. Kearns

J.L. Raaf

L. Wan

T. Wester

J. Bian

B. Cortez

N.J. Griskevich

S. Locke

M.B. Smy

H.W. Sobel

V. Takhistov

A. Yankelevich

J. Hill

M.C. Jang

S.H. Lee

D.H. Moon

R.G. Park

B.S. Yang

B. Bodur

K. Scholberg

C.W. Walter

A. Beauchêne

O. Drapier

A. Ershova

A. Giampaolo

Th. A. Mueller

A.D. Santos

P. Paganini

C. Quach

B. Quilain

R. Rogly

T. Nakamura

J.S. Jang

R.P. Litchfield

L.N. Machado

F.J.P. Soler

J.G. Learned

K. Choi

N. Iovine

S. Cao

L.H.V. Anthony

D. Martin

N.W. Prouse

M. Scott

A.A. Sztuc

Y. Uchida

V. Berardi

N.F. Calabria

M.G. Catanesi

E. Radicioni

Neutron-Multiplicity Measurement in Muon Capture on Oxygen Nuclei in the Gadolinium-Loaded Super-Kamiokande Detector

We present MicroBooNE’s first search for dark sector <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> explanations of the long-standing MiniBooNE anomaly. The MiniBooNE anomaly has garnered significant attention over the past 20 years including previous MicroBooNE investigations into both anomalous electron and photon excesses, but its origin still remains unclear. In this Letter, we provide the first direct test of dark sector models in which dark neutrinos, produced through neutrino-induced scattering, decay into missing energy and visible <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> pairs comprising the MiniBooNE anomaly. Many such models have recently gained traction as a viable solution to the anomaly while evading past bounds. Using an exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>6.87</mn><mo>×</mo><msup><mn>10</mn><mn>20</mn></msup></math> protons-on-target in the Booster Neutrino Beam, we implement a selection targeting forward-going, coherently produced <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> events. After unblinding, we observe 95 events, which we compare with the constrained background-only prediction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>69.7</mn><mo>±</mo><mn>17.3</mn></math>. This analysis sets the world’s first direct limits on these dark sector models and, at the 95% confidence level, excludes the entirety of the single dark neutrino and majority of the dual dark neutrino, parameter space that is viable as a solution to the MiniBooNE anomaly.

Spain

A.M. Abdullahi

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

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

Italy

Poland

J. Hoefken Zink

G.A. Horton-Smith

M. Hostert

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

First Search for Dark Sector <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> Explanations of the MiniBooNE Anomaly at MicroBooNE