Dark kinetic heating of neutron stars has been previously studied as a promising dark matter detection avenue. Kinetic heating occurs when dark matter is sped up to relativistic speeds in the gravitational well of high-escape velocity objects, and deposits kinetic energy after becoming captured by the object, thereby increasing its temperature. We show that dark kinetic heating can be significant even in objects with low-escape velocities, such as exoplanets and brown dwarfs, increasing the discovery potential of such searches. This can occur if there is a long-range dark force, creating a “dark escape velocity”, leading to heating rates substantially larger than those expected from neutron stars. We consequently set constraints on dark sector parameters using Wide-field Infrared Survey Explorer and JWST data on Super-Jupiter WISE 0855-0714, and map out future sensitivity to the dark matter scattering cross section below 10 cm . We compare dark kinetic heating rates of other lower escape velocity objects such as the Earth, Sun, and white dwarfs, finding complementary kinetic heating signals are possible depending on particle physics parameters.

United States

Javier Acevedo

Rebecca Leane

Aidan Reilly

Dark kinetic heating of exoplanets and brown dwarfs

<p>We study the impacts of the squeezing effect caused by in-medium mass modification on the Hanbury- Brown–Twiss (HBT) correlation of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mi>ϕ</mi></mrow></math> using a hydrodynamical source. The squeezing effect reduces the influence of transverse flow on the transverse distribution of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>ϕ</mi></math> emitting source while expanding the longitudinal source distribution. This trend becomes more noticeable as the transverse momentum increases, resulting in an enlargement of the HBT radii for <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mi>ϕ</mi></mrow></math>. Notably, this enlargement is particularly evident with higher transverse pair momentum. As a result, the HBT radii of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mi>ϕ</mi></mrow></math> increase as the transverse pair momentum increases instead of showing a consistent decrease, showcasing the nonflow behavior of HBT radii in hydrodynamical sources. Both Gaussian fitting and Lévy fitting support the conclusion.</p>

China

Yong Zhang

Peng Ru

Hanbury-Brown–Twiss correlation of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ϕ</mi><mi>ϕ</mi></mrow></math> with in-medium mass modification

We propose a novel approach to probe primordial inhomogeneity in hot and dense matter which could be realized in noncentral heavy-ion collisions. Although the Hanbury Brown and Twiss (HBT) interferometry is commonly used to infer the system size, the cluster size should be detected if substructures emerge in space. We demonstrate that a signal peak in the HBT two-particle correlation stands at the relative momentum corresponding to the spatial scale of pseudo one-dimensional modulation. We assess detectability using the data prepared by an event generator (AMPT model) with clustering implemented in the particle distribution.

Japan

Kenji Fukushima

Yoshimasa Hidaka

Katsuya Inoue

Kenta Shigaki

Yorito Yamaguchi

Hanbury-Brown–Twiss signature for clustered substructures probing primordial inhomogeneity in hot and dense QCD matter

Motivated primarily by the large uncertainties in the thermonuclear rate of the $^{30}$P<math><msup><mrow><mo>(</mo><mi>p</mi><mo>,</mo><mi>γ</mi><mo>)</mo></mrow><mrow><mn>31</mn></mrow></msup></math>S reaction that limit our understanding of classical novae, we carried out lifetime measurements of $^{31}$S excited states using the Doppler Shift Lifetimes (DSL2) facility at the TRIUMF Isotope Separator and Accelerator (ISAC-II) facility. The $^{31}$S excited states were populated by the $^{3}$He<math><mo>(</mo><msup><mrow></mrow><mrow><mn>32</mn></mrow></msup></math>S<math><msup><mrow><mo>,</mo><mi>α</mi><mo>)</mo></mrow><mrow><mn>31</mn></mrow></msup></math>S reaction. The deexcitation γ rays were detected by a clover-type high-purity germanium detector in coincidence with the α particles detected by a silicon detector telescope. We have applied modern Markov chain Monte Carlo-based Bayesian statistical techniques to perform lineshape analyses of Doppler-shift attenuation method γ-ray data for the first time. We have determined the lifetimes of the two lowest-lying $^{31}$S excited states. First experimental upper limits on the lifetimes of four higher-lying states have been obtained. The experimental results were compared to shell-model calculations using five universal sd-shell Hamiltonians. Evidence for γ rays originating from the astrophysically important <math><msup><mrow><mi>J</mi></mrow><mrow><mi>π</mi></mrow></msup><mo>=</mo><mn>3</mn><mo>/</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>+</mo></mrow></msup></math>, 260-keV $^{30}$P<math><msup><mrow><mo>(</mo><mi>p</mi><mo>,</mo><mi>γ</mi><mo>)</mo></mrow><mrow><mn>31</mn></mrow></msup></math>S resonance with an excitation energy of <math><msub><mrow><mi>E</mi></mrow><mrow><mi>x</mi></mrow></msub><mo>=</mo><mn>6390.2</mn><mo>(</mo><mn>7</mn><mo>)</mo></math> keV in $^{31}$S has also been observed, although strong constraints on the lifetime will require better statistics.

L.J. Sun

C. Fry

Canada

B. Davids

N. Esker

C. Wrede

M. Alcorta

S. Bhattacharjee

M. Bowry

B.A. Brown

T. Budner

R. Caballero-Folch

L. Evitts

Israel

M. Friedman

A.B. Garnsworthy

B.E. Glassman

G. Hackman

J. Henderson

O.S. Kirsebom

J. Lighthall

P. Machule

J. Measures

M. Moukaddam

South Korea

J. Park

C. Pearson

D. Pérez-Loureiro

C. Ruiz

P. Ruotsalainen

J. Smallcombe

J.K. Smith

D. Southall

J. Surbrook

L.E. Weghorn

United Kingdom

M. Williams

First application of Markov chain Monte Carlo-based Bayesian data analysis to the Doppler-shift attenuation method

The first low-energy Coulomb-excitation measurement of the radioactive, semi-magic, two proton-hole nucleus $^{206}$Hg, was performed at CERN's recently-commissioned HIE-ISOLDE facility. Two γ rays depopulating low-lying states in $^{206}$Hg were observed. From the data, a reduced transition strength <math><mi>B</mi><mo>(</mo><mi>E</mi><mn>2</mn><mo>;</mo><msubsup><mrow><mn>2</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo>→</mo><msubsup><mrow><mn>0</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo>+</mo></mrow></msubsup><mo>)</mo><mo>=</mo><mn>4.4</mn><mo>(</mo><mn>6</mn><mo>)</mo></math> W.u. was determined, the first such value for an <math><mi>N</mi><mo>=</mo><mn>126</mn></math> nucleus south of $^{208}$Pb, which is found to be slightly lower than that predicted by shell-model calculations. In addition, a collective octupole state was identified at an excitation energy of 2705 keV, for which a reduced <math><mi>B</mi><mo>(</mo><mi>E</mi><mn>3</mn><mo>)</mo></math> transition probability of <math><msubsup><mrow><mn>30</mn></mrow><mrow><mo>−</mo><mn>13</mn></mrow><mrow><mo>+</mo><mn>10</mn></mrow></msubsup></math> W.u. was extracted. These results are crucial for understanding both quadrupole and octupole collectivity in the vicinity of the heaviest doubly-magic nucleus $^{208}$Pb, and for benchmarking a number of theoretical approaches in this key region. This is of particular importance given the paucity of data on transition strengths in this region, which could be used, in principle, to test calculations relevant to the astrophysical r-process.

L. Morrison

Poland

K. Hadyńska-Klȩk

Zs. Podolyák

CERN

L.P. Gaffney

France

M. Zielińska

Germany

H. Grawe

P.D. Stevenson

T. Berry

A. Boukhari

M. Brunet

R. Canavan

R. Catherall

Sweden

J. Cederkäll

S.J. Colosimo

J.G. Cubiss

Belgium

H. De Witte

D.T. Doherty

Ch. Fransen

G. Georgiev

Finland

E. Giannopoulos

M. Górska

H. Hess

L. Kaya

T. Kröll

N. Lalović

B. Marsh

Y. Martinez Palenzuela

South Africa

G. O'Neill

J. Pakarinen

J.P. Ramos

P. Reiter

J.A. Rodriguez

D. Rosiak

S. Rothe

M. Rudigier

Italy

M. Siciliano

Australia

E.C. Simpson

J. Snall

P. Spagnoletti

S. Thiel

N. Warr

F. Wenander

R. Zidarova

Quadrupole and octupole collectivity in the semi-magic nucleus Hg

The heavy-ion inelastic scattering of the neutron-rich nucleus $^{29}$Ne to its excited states was studied using a 100.1 MeV/u $^{29}$Ne rare isotope beam on $^{181}$Ta and $^{9}$Be targets. The combined setup consisting of the GRETINA array, the TRIPLEX device and the S800 Spectrograph facilitates the simultaneous measurements of the two inelastic reactions, providing the first measurement of the transition strengths for this isotope. A sizable E2 strength B(E2↑) which amounts to 163(30) e$^{2}$fm$^{4}$ was determined in the excitation to the 931-keV state, demonstrating a large degree of collectivity. The present results of B(E2↑) are compared to various shell-model calculations, confirming the role of intruder configurations in $^{29}$Ne at the boundary of the island of inversion.

A. Revel

J. Wu

H. Iwasaki

J. Ash

D. Bazin

J. Chen

R. Elder

P. Farris

A. Gade

M. Grinder

N. Kobayashi

J. Li

B. Longfellow

Croatia

T. Mijatović

J. Pereira

Spain

A. Poves

A. Sanchez

N. Shimizu

M. Spieker

Y. Utsuno

D. Weisshaar

Large collectivity in Ne at the boundary of the island of inversion

In parts I [1] and II [2] of our earlier work, we studied how metrics g  ij  on   <math> <mi>su</mi> </math>  $$ \mathfrak{su} $$ (n) may spontaneously break symmetry and crystallize into a form which is kaq, knows about qubits. We did this for n = 2 N  and then away from powers of 2. Here we address the Fermionic version and find kam metrics, these know about Majoranas. That is, there is a basis of principal axes {H  k } of which is of homogeneous Majorana degree. In part I, we searched unsuccessfully for functional minima representing crystallized metrics exhibiting the Brown-Susskind penalty schedule, motivated by their study of black hole scrambling time. Here, by segueing to the Fermionic setting we find, to good approximation, kam metrics adhering to this schedule on both   <math> <mi>su</mi> </math>  $$ \mathfrak{su} $$ (4) and   <math> <mi>su</mi> </math>  $$ \mathfrak{su} $$ (8). Thus, with this preliminary finding, our toy model exhibits two of the three features required for the spontaneous emergence of spatial structure: (1) localized degrees of freedom and, (2) a preference for low body-number (or low Majorana number) interactions. The final feature, (3) constraints on who may interact with whom, i.e. a neighborhood structure, must await an effective analytic technique, being entirely beyond what we can approach with classical numerics.

Michael Freedman

Modjtaba Zini

Symmetry breaking to Majorana Brown-Susskind metric

The Brown-York stress tensor provides a means for defining quasilocal gravitational charges in subregions bounded by a timelike hypersurface. We consider the generalization of this stress tensor to null hypersurfaces. Such a stress tensor can be derived from the on-shell subregion action of general relativity associated with a Dirichlet variational principle, which fixes an induced Carroll structure on the null boundary. The formula for the mixed-index tensor T  i  j takes a remarkably simple form that is manifestly independent of the choice of auxiliary null vector at the null surface, and we compare this expression to previous proposals for null Brown-York stress tensors. The stress tensor we obtain satisfies a covariant conservation equation with respect to any connection induced from a rigging vector at the hypersurface, as a result of the null constraint equations. For transformations that act covariantly on the boundary structures, the Brown-York charges coincide with canonical charges constructed from a version of the Wald-Zoupas procedure. For anomalous transformations, the charges differ by an intrinsic functional of the boundary geometry, which we explicity verify for a set of symmetries associated with finite null hyper-surfaces. Applications of the null Brown-York stress tensor to symmetries of asymptotically flat spacetimes and celestial holography are discussed.

Venkatesa Chandrasekaran

Éanna Flanagan

Ibrahim Shehzad

Antony Speranza

Brown-York charges at null boundaries

We compute the Hamiltonian surface charges of gravity for a family of conservative boundary conditions, that include Dirichlet, Neumann, and York’s mixed boundary conditions defined by holding fixed the conformal induced metric and the trace of the extrinsic curvature. We show that for all boundary conditions considered, canonical methods give the same answer as covariant phase space methods improved by a boundary Lagrangian, a prescription recently developed in the literature and thus supported by our results. The procedure also suggests a new integrable charge for the Einstein-Hilbert Lagrangian, different from the Komar charge for non-Killing and non-tangential diffeomorphisms. We study how the energy depends on the choice of boundary conditions, showing that both the quasi-local and the asymptotic expressions are affected. Finally, we generalize the analysis to non-orthogonal corners, confirm the matching between covariant and canonical results without any change in the prescription, and discuss the subtleties associated with this case.

Gloria Odak

Simone Speziale

Brown-York charges with mixed boundary conditions

B.M. Rebeiro

S. Triambak

P.E. Garrett

G.C. Ball

R. Lindsay

P. Adsley

V. Bildstein

C. Burbadge

A. Diaz Varela

T. Faestermann

D.L. Fang

R. Hertenberger

M. Horoi

B. Jigmeddorj

M. Kamil

K.G. Leach

P.Z. Mabika

J.C. Nzobadila Ondze

J.N. Orce

H.F. Wirth

Corrigendum to “Benchmarking Xe neutrinoless Decay Matrix Element Calculations With the Ba( , ) reaction” [Phys. Lett. B 809 (2020) 135702]