A measurement of event-shape variables is presented, using a data sample produced in a special run with approximately one inelastic proton-proton collision per bunch crossing. The data were collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>64</mn><mtext> </mtext><mtext> </mtext><mrow><mi mathvariant="normal">μ</mi><msup><mrow><mi mathvariant="normal">b</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></mrow></math>. A number of observables related to the overall distribution of charged particles in the collisions are corrected for detector effects and compared with simulations. Inclusive event-shape distributions, as well as differential distributions of event shapes as functions of charged-particle multiplicity, are studied. None of the models investigated are able to satisfactorily describe the data. Moreover, there are significant features common amongst all generator setups studied, particularly showing data being more isotropic than any of the simulations. Multidimensional unfolded distributions are provided, along with their correlations.

Armenia

V. Chekhovsky

A. Hayrapetyan

V. Makarenko

A. Tumasyan

Austria

W. Adam

J.W. Andrejkovic

L. Benato

T. Bergauer

S. Chatterjee

K. Damanakis

M. Dragicevic

P.S. Hussain

M. Jeitler

N. Krammer

A. Li

D. Liko

I. Mikulec

J. Schieck

R. Schöfbeck

D. Schwarz

M. Sonawane

W. Waltenberger

C.E. Wulz

Belgium

T. Janssen

H. Kwon

T. Van Laer

P. Van Mechelen

N. Breugelmans

J. D’Hondt

S. Dansana

A. De Moor

M. Delcourt

F. Heyen

Y. Hong

S. Lowette

I. Makarenko

D. Müller

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

M. De Coen

D. Dobur

G. Gokbulut

J. Knolle

L. Lambrecht

D. Marckx

K. Skovpen

N. Van Den Bossche

J. van der Linden

J. Vandenbroeck

L. Wezenbeek

S. Bein

A. Benecke

A. Bethani

G. Bruno

C. Caputo

J. De Favereau De Jeneret

C. Delaere

I.S. Donertas

A. Giammanco

A.O. Guzel

Sa. Jain

V. Lemaitre

J. Lidrych

P. Mastrapasqua

T.T. Tran

S. Turkcapar

Brazil

G.A. Alves

E. Coelho

G. Correia Silva

C. Hensel

T. Menezes De Oliveira

C. Mora Herrera

P. Rebello Teles

M. Soeiro

E.J. Tonelli Manganote

A. Vilela Pereira

W.L. Aldá Júnior

M. Barroso Ferreira Filho

H. Brandao Malbouisson

W. Carvalho

J. Chinellato

Measurement of event shapes in minimum-bias events from 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>

We study the canonical quantization of a massive scalar field on a five dimensional, rotating black hole spacetime. We focus on the case where the spacetime is asymptotically anti-de Sitter and the black hole’s two angular momentum parameters are equal. In this situation the geometry possesses additional symmetries which simplify both the mode solutions of the scalar field equation and the stress-energy tensor. When the angular momentum of the black hole is sufficiently small that there is no speed-of-light surface, there exists a Killing vector which is timelike in the region exterior to the event horizon. In this case classical superradiance is absent and we construct analogs of the usual Boulware and Hartle-Hawking quantum states for the quantum scalar field. We compute the differences in expectation values of the square of the quantum scalar field operator and the stress-energy tensor operator between these two quantum states.

United Kingdom

Alessandro Monteverdi

Elizabeth Winstanley

Quantum scalar field theory on equal-angular-momenta Myers-Perry-AdS black holes

We show that multiparticle contributions to amplitudes of weak decays of the generic topology (heavy quark hits some intermediate point of the propagator line joining the end-points from which momenta $\textit{q}$ and $$q'$$ are emitted) is given in the heavy quark limit and at the leading order in $$\alpha _s$$ by the convolution of (i) hard kernel composed of highly virtual propagators of light degrees of freedom and (ii) the $\textit{B}$-meson multiparticle wave function, $$\langle 0|\phi (x)\phi (x_1)\cdots \phi (x_n)\phi _b(0)\phi (x'_{n'})\cdots \phi (x'_1)\phi (x')|B(p)\rangle $$ , in a $\textit{double-collinear}$ light-cone configuration: the coordinates $$x,x_1,\ldots ,x_n$$ are ordered and aligned along the light-like 4-vector $$a_\mu $$ , $$a^2=0$$ , $$q_\mu \propto a_\mu $$ , while the coordinates $$x',x_1',\ldots ,x'_{n'}$$ are ordered and aligned along the light-like 4-vector $$a'_\mu $$ , $$a'^2=0$$ , $$q'_\mu \propto a'_\mu $$ , $$a'a\ne 0$$ . Corrections to this factorization formula are suppressed by powers of $$\Lambda _\textrm{QCD}/M_B$$ .

Russia

Dmitri Melikhov

Factorization of multiparticle contributions to amplitudes of $\textit{B}$-meson weak decays

Within the framework of an equivparticle model employing mean-field approximation, we investigate systematically the mass spectra of color-singlet <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>-quark configurations with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>=</mo><mn>3</mn></math>, 6, 9, 12, 15, and 18, which are assumed to be spherically symmetric with quarks occupying the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><msub><mrow><mi mathvariant="normal">s</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math> state, i.e., compact multibaryon states. At a given quark number <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math>, these states collectively form a single irreducible representation under SU(6) symmetry. Our analysis yields comprehensive mass formulas that characterize these SU(6) multiplets, providing a unified description of their mass spectra. In order to effectively constrain the parameter space of the model and improve the prediction accuracy, we carry out a Bayesian parameter inference based on the experimental masses of eight baryons and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mn>03</mn></msub></math>. The posterior probability density functions and their correlations of the model parameters are examined, based on which we further predict the masses of various multibaryon states and provide their 68% and 90% credible intervals. In our prediction, H-dibaryon, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>D</mi><mn>03</mn></msub></math>, and the dibaryon with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>6</mn></math> are all bound states relative to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mi mathvariant="normal">Λ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><mi mathvariant="normal">Δ</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Ω</mi><mi mathvariant="normal">Ω</mi></math> thresholds, while slight probabilities of other stable dibaryons (23.64% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ω</mi><mo>−</mo></msup><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> for the state with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>5</mn></math> and 92.49% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup></math> for the state wtih <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>4</mn></math>) and tribaryons (0.25% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> for the state wtih <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>6</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></math>; 2.19% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup></math> for the state with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>5</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>0</mn></math>; and 2.21% more stable than <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi><mi mathvariant="normal">Λ</mi><msup><mi mathvariant="normal">Ξ</mi><mn>0</mn></msup></math> for the state with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mo>=</mo><mo>−</mo><mn>4</mn></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>I</mi><mo>=</mo><mn>1</mn><mo>/</mo><mn>2</mn></math>) are observed as well. For heavier compact multibaryon states, it is unlikely for them to be stable. The stable and unstable multibaryon states examined in this work may persist in compact stars, which could be helpful for us to understand the essence of pulsarlike objects.

China

Hao-Song You

Xinmei Zhu

Cheng-Jun Xia

Jialun Ping

Ren-Xin Xu

Multibaryon states in the framework of an equivparticle model

This study explores the realization of nonminimally coupled Higgs inflation in the context of no-scale supergravity, investigates the formation of primordial black holes, and examines the potential for observable proton decay within the framework of the R-symmetric $\textit{SU}$(5) model. For inflation, both single and multifield scenarios are investigated. The prediction of the single-field model for the tensor-to-scalar ratio, $\textit{r}$, is approximately $$10^{-3}$$ , and the scalar spectral index falls within Planck’s 1 $$\sigma $$ range. The running of the scalar spectral index, $$-{dn_{s}}/{d\ln {k}}$$ , is approximately $$10^{-4}$$ . A realistic scenario of reheating and non-thermal leptogenesis is employed with reheat temperature $$T_r\sim 10^9$$ GeV. In the multifield case, we mainly focus on Primordial Black Holes (PBHs) and Gravitational Waves (GWs). In this inflationary framework, we demonstrate how a suitable choice of parameters can result in an enhanced scalar power spectrum, leading to the production of primordial black holes (PBHs) capable of fully accounting for dark matter. We also show that this scenario leads to Scalar Induced Gravitational Waves (SIGW) which can be detected in current and future GW detectors. We explore different proton decay channels to look for observable predictions for the next-generation proton decay experiments Hyper-K and DUNE consistent with gauge coupling unification and cosmological bounds.

Pakistan

Nadir Ijaz

Maria Mehmood

Saudi Arabia

Mansoor Ur Rehman

The stochastic gravitational-wave background from primordial black holes and observable proton decay in R-symmetric $\textit{SU}$(5) Inflation

Determining the transport properties of quark-gluon plasma is one of the most important aspects of relativistic heavy ion collision studies. Field-theoretical calculations of transport coefficients such as the shear and bulk viscosities require Kubo formulas, which in turn require real-time correlation functions of stress-energy tensors. Consequently, knowing the analytic structure of these correlation functions is essential in any such studies. Using the energy-conservation laws and the results from gravity-hydrodynamics analysis, we determine the low-frequency and low-wavenumber analytic structures of all stress-energy correlation functions in the rest frame of the medium. By comparing with the diffusion and sound spectra from the second-order and third-order relativistic hydrodynamics, various new Kubo formulas are derived in the limit where the zero-frequency limit is taken first. We also show that the meaning of the Kubo formulas for relaxation times can change when higher-order terms are added to the hydrodynamics. A subtle issue of taking the zero frequency and zero wave0number limits when using skeleton diagrams is addressed as well.

Canada

Sangyong Jeon

Poland

Alina Czajka

South Korea

Juhee Hong

Analytic structure of stress-energy response functions and new Kubo formulas

Kinetic equilibration at late times is physically required for heavy particles in a finite temperature medium. In Fokker-Planck dynamics, it is ensured by the Einstein relation between the drag and longitudinal momentum diffusion coefficients. However, in certain gauge field theories, this relation is violated at any nonzero heavy quark velocity. Recent work in strongly coupled <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">N</mi><mo>=</mo><mn>4</mn></math> SYM gauge theory shows that the Kolmogorov equation for the heavy quark phase space distribution (that reduces to Fokker-Planck form upon truncating the momentum transfer probability distribution to second moments) does equilibrate even though the Fokker-Planck equation does not. Going beyond these (to date theory-specific) insights, we derive a universal equilibration condition for the kernel of the Kolmogorov equation and, consequently, for the momentum transfer probability distribution that holds in any quantum field theory with any coupling strength. This condition, which is the generalization of the Einstein relation to quantum field theories which feature non-Gaussian fluctuations, reveals that the asymmetry between energy loss and energy gain in the momentum transfer probability distribution takes a simple, theory-independent, form.

United States

Krishna Rajagopal

Bruno Scheihing-Hitschfeld

CERN

Urs Achim Wiedemann

Universal Equilibration Condition for Heavy Quarks

We present high-precision lattice results for the confined-deconfined interface tension and the latent heat of pure <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SU</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math> gauge theories up to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi><mo>=</mo><mn>10</mn></math> and investigate their asymptotic <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>N</mi></math> dependency. For both quantities we observe the leading <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>N</mi><mn>2</mn></msup></math> behavior and subleading corrections, with the result for the interface tension <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>σ</mi><mo>/</mo><msubsup><mi>T</mi><mi>c</mi><mn>3</mn></msubsup><mo>=</mo><mn>0.0182</mn><mo stretchy="false">(</mo><mn>7</mn><mo stretchy="false">)</mo><msup><mi>N</mi><mn>2</mn></msup><mo>−</mo><mn>0.194</mn><mo stretchy="false">(</mo><mn>15</mn><mo stretchy="false">)</mo></math> and for the latent heat <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>L</mi><mo>/</mo><msubsup><mi>T</mi><mi>c</mi><mn>4</mn></msubsup><mo>=</mo><mn>0.360</mn><mo stretchy="false">(</mo><mn>6</mn><mo stretchy="false">)</mo><msup><mi>N</mi><mn>2</mn></msup><mo>−</mo><mn>1.88</mn><mo stretchy="false">(</mo><mn>17</mn><mo stretchy="false">)</mo></math>. We use the mixed phase ensemble method—where the system is constrained so that half of the volume is in the confined phase and the other half in the deconfined phase—and the interface tension is obtained by measuring the capillary wave fluctuation spectra of the interfaces between the two phases. The method bypasses supercritical slowing down from which other methods for determining the interface tension suffer, and as a by-product produces accurate estimates of the critical inverse gauge coupling as a function of the inverse temperature. We use the latter to determine the lattice beta function values, required to compute the latent heat from the discontinuity in the average plaquette action across the confined-deconfined transition.

Finland

Switzerland

Tobias Rindlisbacher

Kari Rummukainen

Ahmed Salami

Confined-deconfined interface tension and latent heat in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>SU</mi><mo stretchy="false">(</mo><mi>N</mi><mo stretchy="false">)</mo></mrow></math> gauge theory

We develop a localized particle detector model formulated as a massive quantum field on Minkowski spacetime with the spatial origin excised. To render the problem well-posed at the puncture, we impose boundary conditions at the excised point, which we take to be of Robin type. This setup yields a discrete sector, given by bound-state solutions of the radial equation with real, positive frequencies, which characterizes the detector. We construct the full two-point function and show its decomposition into; (i) the discrete radial bound-state sector, (ii) the boundary condition modified continuous sector, and (iii) the unmodified Dirichlet sector. We then compute the detector field’s stress-energy tensor and prove its covariant conservation. For the specific localized modes in this setup, the discrete-sector contribution cancels in the complete stress-energy tensor, leaving only boundary-condition induced terms. Notably, the discrete modes crucial to localized field-based detectors emerge naturally from the boundary conditions, without ad hoc confining potentials, providing a covariant framework that extends the traditional Unruh-DeWitt paradigm. This mechanism is not restricted to Minkowski spacetime; the same construction can be applied to massive fields on backgrounds with naked singularities, such as conical and global monopole spacetimes, offering a unified route to detector localization in a broad class of geometries.

Victor H.M. Ramos

João Paulo M. Pitelli

João C.A. Barata

Invisible extended Unruh-DeWitt detector

The suppression of cosmological structure at small scales is a key signature of dark matter (DM) produced via freeze-in in the low-mass regime. We present a comprehensive analysis of its impact, incorporating recent constraints from Milky Way satellite counts, strong gravitational lensing with James Webb Space Telescope (JWST) data, and the Lyman-<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi></math> forest. We adopt a general strategy to translate existing warm dark matter (WDM) bounds into lower mass limits for a broad class of DM candidates characterized by quasithermal phase space distributions. The benefits of this approach include computational efficiency and the ability to explore a wide range of models. We derive model-independent bounds for DM produced via two-body decays, scatterings, and three-body decays, and apply the framework to concrete scenarios such as the Higgs portal, sterile neutrinos, axionlike particles, and the dark photon portal. Results from specific models confirm the validity of the model-independent analysis.

Italy

Francesco D’Eramo

Israel

Alessandro Lenoci

Ariane Dekker

Dark matter freeze-in and small-scale observables: Novel mass bounds and viable particle candidates