We investigate the frame dependence of distribution functions within the framework of generalized chiral kinetic theory. Based on the derived transformation rules governing the choice of frame, we analytically obtain the global equilibrium solutions in the presence of vorticity and electromagnetic fields. Our results show that, under the assumption of varying electromagnetic fields, these equilibrium solutions can be uniquely determined.

China

Shu-Xiang Ma

Jian-Hua Gao

Frame dependence in generalized chiral kinetic theory * Supported in part by the National Natural Science Foundation of China (12575147, 12321005, 12175123)

We perform a model-independent investigation of the thermodynamic evolution of the Universe by reconstructing the expansion history from observational data using Gaussian Process regression. We consider three independent combinations of datasets, namely CC32+DESI DR2+Pantheon+, CC32+DESI DR2+Union3, and CC32+DESI DR2+DES Y5, allowing us to assess the impact of different supernova samples on the reconstruction. From the reconstructed Hubble parameter and its derivatives over the reconstructed redshift range, we evaluate key thermodynamic quantities associated with the apparent horizon, including the diagnostic function $\textit{P}$($\textit{z}$), the entropy production rate $${{\dot{S}}}_{\textrm{tot}}$$ , and its second derivative $${{\ddot{S}}}_{\textrm{tot}}$$ . Within the observationally reconstructed late-time redshift range, we find that $\textit{P}$($\textit{z}$) remains positive for all dataset combinations, supporting the validity of the generalized second law of thermodynamics. Correspondingly, $${{\dot{S}}}_{\textrm{tot}} > 0$$ throughout, while $${{\ddot{S}}}_{\textrm{tot}} < 0$$ at low redshifts, indicating that the Universe evolves toward stable thermodynamic equilibrium. To assess methodological robustness, the reconstruction is performed using multiple covariance kernels, including the Squared Exponential and Matérn kernels with $$\nu = 5/2, 7/2,$$ and 9/2, all of which yield consistent results within uncertainties. We also reconstruct the dark energy equation of state in a fully model-independent manner and find that the inferred preference for dynamical dark energy is sensitive to both the adopted supernova compilation and the GP kernel, ranging from consistency with $$\Lambda $$ CDM to a moderate ( $$\sim 2$$ – $$4\sigma $$ ) preference for evolving dark energy, with all reconstructions exhibiting a crossing of the $$w=-1$$ boundary at intermediate redshifts.

India

Afaq Maqsood

Tanima Duary

Model-independent reconstruction of cosmic thermodynamics and dark energy dynamics

<p>This Letter reports on the first evidence of inclusive Higgs-boson production at high transverse momentum in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>b</mi><mover accent="true"><mrow><mi>b</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow></math> final state, reconstructed in a single large-radius jet. The results are based on proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider at a center-of-mass energies of 13 and 13.6 TeV, corresponding to a total integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>301</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>fb</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math>. The study profits from the large background suppression provided by the use of a new transformer-based algorithm for jet identification and the sharper mass and transverse momentum, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math>, resolution from a dedicated regression model. The yield relative to the standard model prediction for Higgs bosons produced at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math> larger than 450 GeV is measured to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1.53</mn><mo>±</mo><mn>0.2</mn><msubsup><mrow><mn>7</mn><mo stretchy="false">)</mo></mrow><mrow><mo>−</mo><mn>0.27</mn></mrow><mrow><mo>+</mo><mn>0.33</mn></mrow></msubsup><mrow><mo>±</mo></mrow><mn>0.17</mn></mrow></math>, where the first uncertainty is statistical, the second is experimental systematic, and the third accounts for theory systematic, corresponding to an observed (expected) significance of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3.8</mn><mi>σ</mi><mo stretchy="false">(</mo><mn>2.5</mn><mi>σ</mi><mo stretchy="false">)</mo></math> relative to the background-only hypothesis. Results are also obtained in three Higgs boson <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>p</mi><mi mathvariant="normal">T</mi></msub></math> intervals and found to be compatible with standard model predictions, where the first uncertainty is statistical, the second is experimental systematic, and the third accounts for theory systematic.</p>

France

G. Aad

Norway

E. Aakvaag

United States

B. Abbott

United Arab Emirates

S. Abdelhameed

Germany

K. Abeling

N.J. Abicht

S.H. Abidi

M. Aboelela

Morocco

A. Aboulhorma

Israel

H. Abramowicz

Italy

B.S. Acharya

A. Ackermann

C. Adam Bourdarios

Poland

L. Adamczyk

S.V. Addepalli

United Kingdom

M.J. Addison

J. Adelman

Türkiye

A. Adiguzel

T. Adye

A.A. Affolder

Y. Afik

Spain

M.N. Agaras

A. Aggarwal

Romania

C. Agheorghiesei

A. Ahmad

F. Ahmadov

S. Ahuja

X. Ai

G. Aielli

A. Aikot

M. Ait Tamlihat

Sweden

T.P.A. Åkesson

Japan

D. Akiyama

N.N. Akolkar

S. Aktas

G.L. Alberghi

Canada

J. Albert

Switzerland

U. Alberti

P. Albicocco

S. Alderweireldt

Z.L. Alegria

CERN

M. Aleksa

I.N. Aleksandrov

C. Alexa

Greece

T. Alexopoulos

F. Alfonsi

M. Algren

M. Alhroob

Czechia

B. Ali

H.M.J. Ali

S. Ali

S.W. Alibocus

South Africa

M. Aliev

G. Alimonti

C. Allaire

B.M.M. Allbrooke

D.R. Allen

J.S. Allen

J.F. Allen

Australia

C.S. Alley

E.R. Almazan

A. Aloisio

Argentina

F. Alonso

C. Alpigiani

A. Alvarez Fernandez

M. Alves Cardoso

M.G. Alviggi

M. Aly

Brazil

Y. Amaral Coutinho

C. Amelung

M. Amerl

T. Amezza

B. Amini

K. Amirie

A. Amirkhanov

D. Amperiadou

S. An

C. Anastopoulos

T. Andeen

J.K. Anders

A.C. Anderson

A. Andreazza

S. Angelidakis

A. Angerami

A.V. Anisenkov

A. Annovi

C. Antel

E. Antipov

M. Antonelli

F. Anulli

M. Aoki

T. Aoki

M.A. Aparo

L. Aperio Bella

M. Apicella

C. Appelt

A. Apyan

M. Arampatzi

S.J. Arbiol Val

Evidence of Higgs Boson Inclusive Production at High Transverse Momentum Decaying to a Pair of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>b</mi></math>-Quarks with the ATLAS Detector

<p>The existence of a new spin-zero particle with a mass below the electroweak scale is predicted by several theoretical models. Searches for resonant production of photon pairs at the LHC are able to probe these models. We present a search for a narrow resonance produced through gluon fusion that decays into a pair of photons with an invariant mass between 10 and 70 GeV, using a proton-proton collision dataset from the CMS experiment. This dataset, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>54.4</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, was recorded in 2018 at a center-of-mass energy of 13 TeV using a newly introduced diphoton trigger that enabled exploration of the low-mass diphoton spectrum. No significant excess above the expected background is observed. Upper limits are set on the product of the gluon fusion production cross section and the branching fraction of the diphoton decay of a narrow resonance. An interpretation of these limits within an effective field theory framework for axionlike particles is also provided.</p>

Armenia

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

M. Dragicevic

C. Giordano

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

M. Matthewman

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Shooshtari

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

D. Ocampo Henao

T. Van Laer

P. Van Mechelen

J. Bierkens

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

Y. Hong

P. Kashko

S. Lowette

I. Makarenko

D. Müller

J. Song

S. Tavernier

M. Tytgat

G.P. Van Onsem

S. Van Putte

D. Vannerom

B. Bilin

B. Clerbaux

A.K. Das

I. De Bruyn

G. De Lentdecker

H. Evard

L. Favart

P. Gianneios

A. Khalilzadeh

F.A. Khan

A. Malara

M.A. Shahzad

L. Thomas

M. Vanden Bemden

C. Vander Velde

P. Vanlaer

Search for a narrow resonance with a mass between 10 and 70 GeV decaying to a pair of photons in proton-proton collisions at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>