In 2022, the COMPASS collaboration performed semi-inclusive measurements of deep-inelastic muon-scattering on a transversely polarized deuteron (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>LiD</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>6</mn></mrow></mmultiscripts></mrow></math>) target. From these data, transverse-spin-dependent dihadron asymmetries are extracted using pairs of oppositely charged hadrons. These asymmetries are directly sensitive to the quark transversity distributions and provide an independent handle on these fundamental quantities with respect to the Collins asymmetries measured in single-hadron production. The present results significantly improve upon the previous COMPASS deuteron measurements, which were the only available deuteron data worldwide, and reach a statistical precision comparable to that of the existing proton results from COMPASS. A small but nonzero asymmetry is observed at large Bjorken-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>x</mi></math>, consistent with theoretical expectations. A point-by-point extraction of the valence-quark transversity distributions yields, in particular, a substantially improved determination of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>d</mi></math>-quark transversity. These measurements represent a major step towards a complete flavor mapping of the transverse-spin structure of the nucleon.

G.D. Alexeev

Italy

M.G. Alexeev

C. Alice

A. Amoroso

United States

V. Andrieux

V. Anosov

Armenia

S. Asatryan

Czechia

K. Augsten

Poland

W. Augustyniak

Portugal

C.D.R. Azevedo

B. Badelek

Germany

R. Beck

J. Beckers

France

Y. Bedfer

V. Benesova

CERN

J. Bernhard

F. Bradamante

A. Bressan

Taiwan

W.C. Chang

C. Chatterjee

M. Chiosso

S.U. Chung

A. Cicuttin

M.L. Crespo

D. D’Ago

S. Dalla Torre

India

S.S. Dasgupta

S. Dasgupta

M. Dehpour

F. Delcarro

I. Denisenko

O. Yu. Denisov

S.V. Donskov

Japan

N. Doshita

Ch. Dreisbach

W. Dünnweber

R.R. Dusaev

D. Ecker

P. Faccioli

M. Faessler

M. Finger

H. Fischer

K.J. Flöthner

W. Florian

J.M. Friedrich

V. Frolov

L.G. Garcia Ordòñez

O.P. Gavrichtchouk

S. Gerassimov

J. Giarra

D. Giordano

A. Grasso

A. Gridin

M. Grosse Perdekamp

B. Grube

M. Grüner

A. Guskov

P. Haas

D. von Harrach

M. Hoffmann

A. Hoghmrtsyan

N. d’Hose

C.Y. Hsieh

S. Ishimoto

A. Ivanov

T. Iwata

V. Jary

E. Jelinkova

R. Joosten

E. Kabuß

F. Kaspar

A. Kerbizi

B. Ketzer

G.V. Khaustov

T. Klasek

J.H. Koivuniemi

V.N. Kolosov

K. Kondo Horikawa

I. Konorov

A. Yu. Korzenev

A.M. Kotzinian

O.M. Kouznetsov

A. Koval

F. Kunne

K. Kurek

R.P. Kurjata

A. Kveton

K. Lavickova

S. Levorato

Y.S. Lian

Israel

J. Lichtenstadt

P.J. Lin

R. Longo

V.E. Lyubovitskij

A. Maggiora

N. Makke

G.K. Mallot

A. Maltsev

A. Martin

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

Antideuterons and antihelium nuclei in the cosmic-ray spectrum have long been considered a smoking gun signature of dark matter annihilation, making the tentative observation of several such events by AMS highly intriguing. Conventional dark matter models, however, can produce only up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></math> antideuteron events at AMS and are not capable of generating observable fluxes of antihelium. In this Letter, we propose a class of models in which dark matter annihilates into particles carrying baryon and lepton number, whose subsequent decays produce enhanced fluxes of antinucleons and antinuclei. Such scenarios are motivated by grand unified theories and can lead to an order-of-magnitude or larger enhancement in the resulting antideuteron and antihelium-3 fluxes, providing a means by which to potentially explain the events reported by the AMS Collaboration.

Caleb Gemmell

Dan Hooper

Seth Koren

Fabrizio Vassallo

Dark Matter, Baryon Number, and Cosmic-Ray Antinuclei

We present the first simultaneous global QCD analysis of unpolarized transverse momentum dependent (TMD) and collinear parton distribution functions (PDFs) in the proton. Our Letter incorporates data from deep-inelastic scattering, Drell-Yan, inclusive weak boson, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi><mo>+</mo></math> charm, and jet production involving PDFs, as well as TMD Drell-Yan and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>Z</mi></mrow></math>-boson production data from fixed target and collider experiments sensitive to both TMD and collinear distributions. The analysis is performed at next-to-next-to-leading logarithmic accuracy for QCD resummation in TMD observables and next-to-leading order for observables described in collinear factorization. The combined analysis improves knowledge of both TMD and collinear PDFs, particularly in the sea-quark sector, providing a consistent simultaneous description of the aforementioned observables.

P.C. Barry

A. Prokudin

T. Anderson

C. Cocuzza

L. Gamberg

W. Melnitchouk

E. Moffat

D. Pitonyak

J.W. Qiu

N. Sato

Spain

A. Vladimirov

R.M. Whitehill

First Simultaneous Analysis of Transverse Momentum Dependent and Collinear Parton Distributions in the Proton

The production of two isolated photons at the Large Hadron Collider has applications in Higgs-boson phenomenology and in new-physics searches. In fact, measurements would provide more insight if a percent-level theoretical prediction were available. We account for next-to-next-to-next-to-leading-order strong-interaction effects in the cross section for the first time. This is not only necessary to demonstrate the convergence of perturbation theory, but also results in a reduction of the theoretical uncertainty by a factor of 3 down to 3%. With this, we pave the way to improved analyses.

Michał Czakon

Felix Eschment

United Kingdom

Terry Generet

Rene Poncelet

Next-to-Next-to-Next-to-Leading-Order QCD Corrections to Photon-Pair Production

Dense neutrino plasmas can develop instabilities that drive collisionless flavor exchange, equivalent to the emission of flavomons, the quanta of flavor waves. We treat these waves as independent linear degrees of freedom and develop a quasilinear theory, including backreaction on the neutrino distribution and nonresonant neutrino-flavomon interactions, while neglecting wave-wave processes. In a statistically homogeneous, axisymmetric model, the saturated neutrino and flavomon distributions agree closely with periodic-box solutions of the original quantum kinetic equation. Our results provide the first theoretical interpretation for the numerical observations. They also show that flavomon phases have little influence on the final state, supporting the quasilinear theory as a framework for capturing flavor evolution without resolving nonlinear small-scale dynamics.

Damiano F.G. Fiorillo

Georg G. Raffelt

Quasilinear Theory of Fast Flavor Instabilities

The COHERENT Collaboration reports the most precise measurement of the coherent elastic neutrino-nucleus scattering cross section to date. This measurement was performed with COHERENT’s germanium detector array, Ge-Mini, at the Spallation Neutron Source at Oak Ridge National Laboratory. A cumulative exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>4.69</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>22</mn></mrow></msup></mrow></math> protons on target yielded a total number of observed counts of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msubsup><mrow><mn>124</mn></mrow><mrow><mo>−</mo><mn>12</mn></mrow><mrow><mo>+</mo><mn>14</mn></mrow></msubsup></mrow></math> and a flux-averaged cross section of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0.98</mn><mo>±</mo><mn>0.10</mn><mrow><mo stretchy="false">(</mo><mi>statistical</mi><mo stretchy="false">)</mo></mrow><mo>±</mo><mn>0.10</mn><mrow><mo stretchy="false">(</mo><mi>systematic</mi><mo stretchy="false">)</mo></mrow></mrow></math> relative to the standard-model expectation of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>5.9</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>39</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>. The well-understood energy and timing distributions of the neutrino source allow for independent measurements of muon- and electron-neutrino scattering rates. This information is used to improve constraints on nonstandard neutrino interactions mediated by heavy particles.

M. Adhikari

South Korea

M. Ahn

D. Amaya Matamoros

P.S. Barbeau

Russia

V. Belov

I. Bernardi

C. Bock

A. Bolozdynya

R. Bouabid

A. Bracho

J. Browning

B. Cabrera-Palmer

N. Cedarblade-Jones

China

S. Chen

A.I. Colón Rivera

V. da Silva

Y. Efremenko

S.R. Elliott

Canada

A. Erlandson

L. Fabris

S. Foster

A. Galindo-Uribarri

E. Granados Vazquez

M.P. Green

B. Hackett

J. Hakenmüller

M. Harada

M.R. Heath

S.C. Hedges

Y. Hino

H. Huang

W. Huang

H. Jeong

B.A. Johnson

T. Johnson

H. Jones

A. Khromov

D. Kim

C. Koh

L. Kong

A. Konovalov

Y. Koshio

A. Kumpan

O. Kyzylova

Y. Lee

S.M. Lee

G. Li

L. Li

Z. Li

J.M. Link

Measurement of Coherent Elastic Neutrino-Nucleus Scattering on Germanium by COHERENT