We study the chiral symmetry breaking effects of helical magnetic fields in a simple bottom up AdS/CFT model. We explore the instability of the chirally symmetric solution in the presence of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> field and see how it switches off as the wave vector of the helix, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>k</mi></math>, rises, resulting in a first order transition. At low energies the model averages over the helix and the magnetic field is not seen. We show that other sources of chiral symmetry breaking are not directly affected by the helical <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi></math> field. We provide examples of both magnetic catalysis and inverse magnetic catalysis which switch off at large <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>k</mi></math>.

United Kingdom

Nick Evans

Wanxiang Fan

Chiral symmetry restoration for helical magnetic fields in holography

Motivated by the work of Longhi and Materassi, who constructed a realization of the (centerless) <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra for the massive Klein-Gordon field in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>+</mo><mn>1</mn></math> dimensions, we build a realization of the (centerless) massless <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra including superrotations. This realization depends only on the momenta in the light cone expressed in celestial coordinates without any reference to the Klein-Gordon field. The quadratic Casimir of the Lorentz algebra is written in terms of a second order differential operator and the volume form plays an essential role in this construction. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra in terms of vector fields shows its kinematical nature, like the Poincaré algebra. We also construct a dynamical realization of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> from the symplectic structure on the solutions of the massless four-dimensional Klein-Gordon field in terms of quadratic expressions of the Fourier modes and plane waves invariant under translations. Using the Mellin transform, we rewrite the Klein-Gordon field in terms of the boost invariant basis, and write down the corresponding <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> realization. We also provide the relation with spherical harmonics, linking our results with the solutions of Longhi-Materassi, which are in fact a subset of ours.

Spain

Carles Batlle

Italy

Roberto Casalbuoni

Daniele Dominici

José Figueroa-O’Farrill

Joaquim Gomis

Celestial kinematical interpretation for an extended <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>BMS</mi></mrow><mrow><mn>4</mn></mrow></msub></mrow></math> algebra

Charged-current neutrino interactions with final states containing zero mesons and at least one proton are of high interest for current and future accelerator-based neutrino oscillation experiments. Using the Booster Neutrino Beam and the MicroBooNE detector at Fermi National Accelerator Laboratory, we have obtained the first double-differential cross-section measurements of this channel for muon neutrino scattering on an argon target with a leading proton momentum threshold of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0.25</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi><mo>/</mo><mrow><mi>c</mi></mrow></mrow></math>. We also report a flux-averaged total cross section of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>σ</mi><mo>=</mo><mo stretchy="false">(</mo><mn>11.8</mn><mo>±</mo><mn>1.2</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>38</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>cm</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>/</mo><mi>Ar</mi></mrow></math> and several single-differential measurements which extend and improve upon previous results. Statistical and systematic uncertainties are quantified with a full treatment of correlations across 359 kinematic bins, including correlations between distributions describing different observables. The resulting dataset provides the most detailed information obtained to date for testing models of mesonless neutrino-argon scattering.

United States

P. Abratenko

O. Alterkait

D. Andrade Aldana

L. Arellano

J. Asaadi

Israel

A. Ashkenazi

S. Balasubramanian

B. Baller

G. Barr

D. Barrow

J. Barrow

V. Basque

L. Bathe-Peters

O. Benevides Rodrigues

S. Berkman

A. Bhanderi

A. Bhat

M. Bhattacharya

M. Bishai

A. Blake

B. Bogart

T. Bolton

J.Y. Book

M.B. Brunetti

L. Camilleri

Y. Cao

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

A. Devitt

Switzerland

R. Diurba

Z. Djurcic

R. Dorrill

K. Duffy

S. Dytman

B. Eberly

P. Englezos

A. Ereditato

J.J. Evans

R. Fine

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

O. Hen

C. Hilgenberg

G.A. Horton-Smith

Z. Imani

B. Irwin

M.S. Ismail

C. James

China

X. Ji

J.H. Jo

R.A. Johnson

Y.J. Jwa

D. Kalra

N. Kamp

G. Karagiorgi

W. Ketchum

M. Kirby

T. Kobilarcik

I. Kreslo

N. Lane

I. Lepetic

J.Y. Li

Y. Li

K. Lin

B.R. Littlejohn

H. Liu

W.C. Louis

X. Luo

C. Mariani

D. Marsden

J. Marshall

N. Martinez

D.A. Martinez Caicedo

S. Martynenko

Measurement of single- and double-differential cross sections for mesonless charged-current muon neutrino interactions on argon with final-state protons using the MicroBooNE detector

The particle origin of dark matter (DM) remains elusive despite decades of direct, indirect, and collider searches. Several groups have reported a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi></math>-ray excess toward the Galactic Center commonly referred to as the Galactic Center excess (GCE). Its spectrum is consistent with annihilation of weakly interacting massive particles (WIMPs) of mass <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>10</mn><mo>−</mo><mn>100</mn><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> and a thermal-relic cross section. Although many concrete WIMP models reproduce the GCE spectrum, most are now excluded by direct detection experiments that are approaching the neutrino floor. We investigate a class of anomaly-free extensions of the Standard Model featuring gauged differences of lepton number, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>i</mi></msub><mo>−</mo><msub><mi>L</mi><mi>j</mi></msub></mrow></msub></math>, and gauged baryon minus lepton number, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><mi>B</mi><mo>−</mo><mi>L</mi></mrow></msub></math>. We show that these models can reproduce the GCE while remaining compatible with the observed relic abundance. We then impose collider and direct detection constraints, accounting for both tree-level and loop-induced kinetic mixing. The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>e</mi></msub></math> model gives the best fit to the GCE: a DM mass of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>m</mi></mrow><mrow><mi>χ</mi></mrow></msub><mo>∼</mo><mn>40</mn><mo>−</mo><mn>50</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> remains consistent with the muon and electron magnetic moment anomalies, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mi>g</mi><mo>−</mo><mn>2</mn><msub><mo stretchy="false">)</mo><mrow><mi>μ</mi><mo>,</mo><mi>e</mi></mrow></msub></math>, as well as current collider and direct detection limits, for mediator masses in the range <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi>m</mi></mrow><mrow><msup><mrow><mi>A</mi></mrow><mrow><mo>′</mo></mrow></msup></mrow></msub><mo>∼</mo><mn>70</mn><mo>−</mo><mn>86</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></mrow></math> and a DM mediator coupling of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>1</mn><mo>−</mo><mn>5</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></mrow></math>. By contrast, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>e</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></math> models yield poorer fits; satisfying both the relic density and experimental bounds forces the DM mass to lie very close to resonance (i.e. approximately half the mediator mass). Finally, while the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>B</mi><mo>−</mo><mi>L</mi></math> model also matches the GCE well, its parameter space is almost entirely ruled out by strong direct detection limits, except for the narrow resonance region where <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mi>χ</mi></msub></math> should be equal to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msup><mi>A</mi><mo>′</mo></msup></msub><mo>/</mo><mn>2</mn></math> requiring a fine-tuning at the few-percent level.

Jordan Koechler

Mattia Di Mauro

Leptophilic dark matter in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mrow><msub><mi>L</mi><mi>i</mi></msub><mo>−</mo><msub><mi>L</mi><mi>j</mi></msub></mrow></msub></math> models: A solution to the Fermi-LAT Galactic Center excess consistent with cosmological and laboratory observations

We consider diffeomorphism invariant theories of gravity with arbitrary higher derivative corrections to the two derivative Einstein’s theory in the presence of Proca fields—vector fields without <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></math> gauge invariance. We prove that, in such theories, the surface gravity remains constant across the Killing horizon of stationary black hole solutions, without requiring the existence of a bifurcation surface. Our analysis is carried out within an effective field theory framework, where higher derivative contributions are treated perturbatively around the two derivative theory. The proof relies on specific components of the coupled gravity—Proca field equations together with constraints implied by the near horizon boost symmetry of stationary black hole geometries, analyzed using boost-weight arguments. Implementing these arguments in the presence of Proca fields introduces new subtleties beyond those encountered in the pure gravity case. We provide a systematic resolution of these subtleties and demonstrate that the surface gravity remains constant to all orders in the perturbative expansion, thereby establishing the zeroth law. Finally, we outline how this framework can be generalized to broader classes of vector theories with four propagating degrees of freedom, which exhibit qualitative differences from both the Proca and gauge invariant vector theories.

India

Parthajit Biswas

Alokananda Kar

Anowar Shaikh

Zeroth law of black hole thermodynamics for higher derivative Proca theories

A search for the decay $\textit{B}$ $\textit{→ ϕϕ}$ is made using $\textit{pp}$ collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb . No significant signal is observed, and an upper limit on the branching fraction of 1$\textit{.}$3 (1$\textit{.}$4) × 10 at 90 (95)% confidence level is set. This result supersedes the previous LHCb study and improves the upper limit by a factor of two.

Netherlands

R. Aaij

A. Abdelmotteleb

C. Abellan Beteta

F. Abudinén

T. Ackernley

A. Adefisoye

B. Adeva

M. Adinolfi

Sweden

P. Adlarson

France

C. Agapopoulou

C. Aidala

Z. Ajaltouni

S. Akar

K. Akiba

P. Albicocco

Germany

J. Albrecht

Lithuania

R. Aleksiejunas

F. Alessio

Z. Aliouche

P. Alvarez Cartelle

R. Amalric

Brazil

S. Amato

J. Amey

Y. Amhis

L. An

L. Anderlini

M. Andersson

P. Andreola

M. Andreotti

S. Andres Estrada

A. Anelli

D. Ao

F. Archilli

Z. Areg

M. Argenton

Costa Rica

S. Arguedas Cuendis

A. Artamonov

M. Artuso

E. Aslanides

R. Ataíde Da Silva

M. Atzeni

B. Audurier

J. Authier

D. Bacher

I. Bachiller Perea

S. Bachmann

M. Bachmayer

J. Back

P. Baladron Rodriguez

V. Balagura

A. Balboni

W. Baldini

L. Balzani

H. Bao

J. Baptista de Souza Leite

C. Barbero Pretel

M. Barbetti

I. Barbosa

R. Barlow

M. Barnyakov

S. Barsuk

W. Barter

J. Bartz

Search for the decay $\textit{B}$