The cross sections for the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mi>p</mi><mo>→</mo><mi>p</mi><mi>p</mi><mi>η</mi></mrow></math> reaction are evaluated at energies relevant for the HADES, PANDA, and SIS100 experiments at GSI-FAIR (Facility for Antiproton and Ion Research). Consideration includes the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>η</mi></math>-bremsstrahlung mechanism involving intermediate proton exchange via the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>π</mi><mn>0</mn></msup></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>η</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mi>ρ</mi><mn>0</mn></msup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>ω</mi></math> exchanges and the mechanism involving the nucleon resonances <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>N</mi><mo>(</mo><mn>1535</mn><mo>)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>N</mi><mo>(</mo><mn>1650</mn><mo>)</mo></mrow></math>, <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>N</mi><mo>(</mo><mn>1710</mn><mo>)</mo></mrow></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>N</mi><mo>(</mo><mn>1880</mn><mo>)</mo></mrow></math> excited via the pseudoscalar- and/or vector-meson exchanges, depending on the model. The role of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>ω</mi><mi>ω</mi></mrow></math>- and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>ρ</mi><mn>0</mn></msup><msup><mi>ρ</mi><mn>0</mn></msup></mrow></math>-fusion processes with the Reggeized vector-meson exchanges is also discussed. The calculation is done in an effective Lagrangian approach. To determine the parameters of the model, the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>γ</mi><mi>p</mi><mo>→</mo><mi>η</mi><mi>p</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>π</mi><mo>−</mo></msup><mi>p</mi><mo>→</mo><mi>η</mi><mi>n</mi></mrow></math> reactions are studied and the results are then compared with the Crystal Ball and CLAS data. For the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mi>p</mi><mo>→</mo><mi>p</mi><mi>p</mi><mi>η</mi></mrow></math> reaction, the model results are compared with the energy dependence of the cross section measured far from the threshold and with the differential distributions <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>d</mi><mi>σ</mi><mo>/</mo><mi>d</mi><mo form="prefix">cos</mo><msub><mi>θ</mi><mi>η</mi></msub></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>d</mi><mi>σ</mi><mo>/</mo><mi>d</mi><msub><mi>p</mi><mi>η</mi></msub></mrow></math> measured by the DISTO Collaboration. The comparison shows that the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>N</mi><mo>(</mo><mn>1535</mn><mo>)</mo></mrow></math> resonance is the dominant contribution and that other contributions are also important due to interference effects. Assuming that the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>ρ</mi></math> exchange is the dominant resonant excitation process, the model is able to describe the available data, e.g., it reproduces the shape of the angular distributions measured by the DISTO Collaboration. Predictions are given for the HADES experiment at center-of-mass energy of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>3.46</mn></mrow></math> GeV, which can be verified in the near future, and for planned PANDA and SIS100 experiments at higher energies.

Piotr Lebiedowicz

Exclusive <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>η</mi></math> production in proton-proton collisions at energies available at the GSI Facility for Antiproton and Ion Research

In this work, we address the problem of longitudinal spin polarization of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Λ</mi></math> hyperons produced in relativistic heavy-ion collisions. We combine a relativistic kinetic-theory framework that includes spin degrees of freedom treated in a classical way with the freeze-out parametrization used in previous investigations. The use of the kinetic theory allows us to incorporate dissipative corrections (due to the thermal shear and gradients of thermal vorticity) into the Pauli-Lubanski vector that determines spin polarization and can be directly compared with the experimental data. As in earlier similar studies, it turns out that a successful description of data can only be achieved with additional assumptions—in our case, they involve the use of projected thermal vorticity and a suitably adjusted time for spin relaxation (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>τ</mi><mi>s</mi></msub></math>). From our analysis, we find that <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>τ</mi><mi>s</mi></msub><mo>∼</mo><mn>5</mn></mrow><mspace width="4pt"></mspace><mrow><mi>fm</mi><mo>/</mo><mi>c</mi></mrow></math>, which is comparable with other estimates.

India

Soham Banerjee

Poland

Samapan Bhadury

Wojciech Florkowski

Amaresh Jaiswal

Radoslaw Ryblewski

Longitudinal spin polarization in a thermal model with dissipative corrections

Double deeply virtual Compton scattering (DDVCS) is a promising channel for generalized parton distribution (GPD) studies as it is a generalization of the deeply virtual Compton-scattering (DVCS) and timelike Compton-scattering (TCS) processes. In contrast to DVCS and TCS, the GPD phase space accessed through DDVCS is not constrained by on-shell conditions on the incoming and outgoing photons, thus allowing unrestricted GPD extraction from experimental observables. Considering polarized electron and positron beams directed to a polarized proton target, we study the sensitivity of the DDVCS cross-section asymmetries to the chiral-even proton GPDs from different model predictions. The feasibility of such measurements is further investigated in the context of the CLAS and SoLID spectrometers at the Thomas Jefferson National Accelerator Facility and the future Electron-Ion Collider at the Brookhaven National Laboratory.

France

J.S. Alvarado

M. Hoballah

E. Voutier

Sensitivity of double deeply virtual Compton-scattering observables to generalized parton distributions

The elementary fragmentation function that describes the process <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>q</mi><mo>→</mo><mi>π</mi></mrow></math> is predicted by applying crossing and charge symmetry to the cut diagram of the pion valence quark distribution function. This elementary probability distribution defines the ladder-kernel of a quark jet fragmentation equation, which is solved self-consistently to obtain the full pion fragmentation function. The hadronization into a pion employs the complete Poincaré invariant Bethe-Salpeter wave function, though the overwhelming contribution to the fragmentation function is due to the leading Bethe-Salpeter amplitude. Compared to a Nambu–Jona–Lasinio model prediction, the fragmentation function we obtain is enhanced in the range <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>z</mi><mo>≲</mo><mn>0.8</mn></mrow></math> but otherwise in good qualitative agreement. The full pion fragmentation function is overall greater than the elementary fragmentation function below <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>z</mi><mo>≲</mo><mn>0.6</mn></mrow></math>.

Brazil

Roberto Correa da Silveira

Colombia

Fernando E. Serna

Bruno El-Bennich

Pion fragmentation functions from a quark-jet model in a functional approach

An investigation of high-transverse-momentum (high-<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math>) photon-triggered jets in proton-proton (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mtext>−</mtext><mi>p</mi></mrow></math>) and ion-ion (<math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>A</mi><mtext>−</mtext><mi>A</mi></mrow></math>) collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>0.2</mn></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>5.02</mn><mspace width="0.28em"></mspace><mi>TeV</mi></mrow></math> is carried out, using the multistage description of in-medium jet evolution. Monte Carlo simulations of hard scattering and energy loss in heavy-ion collisions are performed using parameters tuned in a previous study of the nuclear modification factor (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mrow><mi>A</mi><mi>A</mi></mrow></msub></math>) for inclusive jets and high-<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math> hadrons. We obtain a good reproduction of the experimental data for photon-triggered jet <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mrow><mi>A</mi><mi>A</mi></mrow></msub></math>, as measured by the ATLAS detector, the distribution of the ratio of jet to photon <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math> (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>X</mi><mrow><mi>J</mi><mi>γ</mi></mrow></msub></math>), measured by both CMS and ATLAS, and the photon-jet azimuthal correlation as measured by CMS. We obtain a moderate description of the photon-triggered jet <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>I</mi><mrow><mi>A</mi><mi>A</mi></mrow></msub></math>, as measured by STAR. A noticeable improvement in the comparison is observed when one goes beyond prompt photons and includes bremsstrahlung and decay photons, revealing their significance in certain kinematic regions, particularly at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msub><mi>X</mi><mrow><mi>J</mi><mi>γ</mi></mrow></msub><mo>&gt;</mo><mn>1</mn></mrow></math>. Moreover, azimuthal angle correlations demonstrate a notable impact of bremsstrahlung photons on the distribution, emphasizing their role in accurately describing experimental results. This work highlights the success of the multistage model of jet modification to straightforwardly predict (this set of) photon-triggered jet observables. This comparison, along with the role played by bremsstrahlung photons, has important consequences on the inclusion of such observables in a future Bayesian analysis.

United States

C. Sirimanna

Japan

Y. Tachibana

A. Majumder

A. Angerami

R. Arora

S.A. Bass

Y. Chen

R. Datta

Canada

L. Du

R. Ehlers

Germany

H. Elfner

R.J. Fries

C. Gale

China

Y. He

B.V. Jacak

P.M. Jacobs

S. Jeon

Y. Ji

F. Jonas

L. Kasper

M. Kordell

A. Kumar

R. Kunnawalkam-Elayavalli

J. Latessa

Y.J. Lee

United Kingdom

R. Lemmon

M. Luzum

S. Mak

A. Mankolli

C. Martin

H. Mehryar

T. Mengel

C. Nattrass

J. Norman

C. Parker

J.F. Paquet

J.H. Putschke

H. Roch

G. Roland

B. Schenke

L. Schwiebert

A. Sengupta

C. Shen

M. Singh

D. Soeder

R.A. Soltz

Finland

I. Soudi

J. Velkovska

G. Vujanovic

X.N. Wang

X. Wu

W. Zhao

Hard-photon-triggered jets in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>p</mi><mtext>−</mtext><mi>p</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>A</mi><mtext>−</mtext><mi>A</mi></mrow></math> collisions

Right-handed weak currents (RHCs) in the left-right symmetric model for neutrinoless double beta decays (DBDs) of both the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mn>0</mn><mo>+</mo></msup><mspace width="3.33333pt"></mspace><mo>→</mo><mspace width="3.33333pt"></mspace><msup><mn>0</mn><mo>+</mo></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mn>0</mn><mo>+</mo></msup><mspace width="3.33333pt"></mspace><mo>→</mo><mspace width="3.33333pt"></mspace><msup><mn>2</mn><mo>+</mo></msup></mrow></math> transitions are discussed from both theoretical and experimental viewpoints. <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>λ</mi><mo>〉</mo></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>η</mi><mo>〉</mo></mrow></math> terms are related by <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>λ</mi><mo>〉</mo><mo>/</mo><mo>〈</mo><mi>η</mi><mo>〉</mo><mo>≈</mo><mo form="prefix">tan</mo><mi>β</mi></mrow></math>, which is constrained in the regions of 1–60 for SUSY grand unified theories (GUTs) and of 1–165 for non-SUSY GUTs. The enhancement mechanisms of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>η</mi><mo>〉</mo></mrow></math> term over the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>λ</mi><mo>〉</mo></mrow></math> term in the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mn>0</mn><mo>+</mo></msup></math> transition is shown, and the <math xmlns="http://www.w3.org/1998/Math/MathML"><mi mathvariant="normal">Δ</mi></math> isobar contribution to the nuclear matrix element (NME) for the transition to the <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mn>2</mn><mo>+</mo></msup></math> state is found to be of the order of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mn>20</mn><mo>%</mo></mrow></math> of the NME with the quenched weak coupling. The new and interesting RHC regions of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>λ</mi><mo>〉</mo><mo>≈</mo><mn>5</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>8</mn></mrow></msup></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>〈</mo><mi>η</mi><mo>〉</mo><mo>≈</mo><mn>1.5</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>10</mn></mrow></msup></mrow></math> are shown to be exclusively explored by measuring both the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>β</mi><mi>β</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>γ</mi></math> rays associated with the ground and excited DBDs by means of the ton-scale DBD detectors for the inverted hierarchy <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>ν</mi></math> masses. The actual RHCs to be studied depend on the RHC NMEs.

Hiroyasu Ejiri

Takeshi Fukuyama

Toru Sato

Right-handed weak currents in neutrinoless <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>β</mi><mi>β</mi></mrow></math> decays and ton-scale <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>β</mi><mi>β</mi></mrow></math> detectors

We employ an equal-velocity quark combination model to study anisotropic flows <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>2</mn></msub><mo>,</mo><mo> </mo><msub><mi>v</mi><mn>3</mn></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>4</mn></msub></math> of identified hadrons at midrapidity in heavy-ion collisions at Relativistic Heavy Ion Collider energies. Under the equal-velocity combination mechanism of constituent quarks at hadronization, we build analytical formulas of anisotropic flows of hadrons in terms of those of quarks just before hadronization. We systematically analyze the contribution of higher-order flows of quarks, and show how simple formulas of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>2</mn></msub><mo>,</mo><mo> </mo><msub><mi>v</mi><mn>3</mn></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>4</mn></msub></math> of identified hadrons with the desired precision can be obtained by neglecting the small contribution of higher-order flows of quarks. We systematically test these simple formulas of hadronic flows by the experimental data of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>2</mn></msub><mo>,</mo><mo> </mo><msub><mi>v</mi><mn>3</mn></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>4</mn></msub></math> of identified hadrons <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>ϕ</mi><mo>,</mo><mo> </mo><mi mathvariant="normal">Λ</mi><mo>,</mo><mo> </mo><msup><mi mathvariant="normal">Ξ</mi><mo>−</mo></msup><mo>,</mo><mo> </mo><msup><mi mathvariant="normal">Ω</mi><mo>−</mo></msup><mo>,</mo><mo> </mo><mover accent="true"><mi mathvariant="normal">Λ</mi><mo>¯</mo></mover><mo>,</mo><mo> </mo><msup><mover accent="true"><mi mathvariant="normal">Ξ</mi><mo>¯</mo></mover><mo>+</mo></msup><mo>,</mo><mo> </mo><msup><mover accent="true"><mi mathvariant="normal">Ω</mi><mo>¯</mo></mover><mo>+</mo></msup><mo>,</mo><mo> </mo><mi>p</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><mover accent="true"><mi>p</mi><mo>¯</mo></mover></math> in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>19.6</mn></mrow></math>, 54.4, and 200 GeV, and we find that the equal-velocity quark combination model can well describe the measured <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>2</mn></msub><mo>,</mo><mo> </mo><msub><mi>v</mi><mn>3</mn></msub></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>v</mi><mn>4</mn></msub></math> of identified hadrons in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at those collision energies. We further study the obtained anisotropic flows of quarks and find two scaling properties which can be qualitatively understood by the hydrodynamic evolution of the thermal quark medium produced in relativistic heavy-ion collisions.

Yan-ting Feng

Rui-qin Wang

Feng-lan Shao

Jun Song

Anisotropic flows of identified hadrons in the equal-velocity quark combination model at energies available at the BNL Relativistic Heavy Ion Collider

We present a novel Monte Carlo implementation of the EKRT model, MC-EKRT, for computing partonic initial states in high-energy nuclear collisions. Our new MC-EKRT event generator is based on collinearly factorized, dynamically fluctuating perturbative QCD (pQCD) minijet production, supplemented with a saturation conjecture that controls the low-<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math> particle production. Previously, the EKRT model has been very successful in describing low-<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>p</mi><mi>T</mi></msub></math> observables at midrapidity in heavy-ion collisions at energies available at the CERN Large Hadron Collider (LHC) and the BNL Relativistic Heavy Ion Collider (RHIC). As novel features, our new MC implementation gives a full three-dimensional initial state event by event, includes dynamical minijet-multiplicity fluctuations in the saturation and particle production, introduces a new type of spatially dependent nuclear parton distribution functions, and accounts for the conservation of energy/momentum and valence-quark number. In this proof-of-principle study, we average a large set of event-by-event MC-EKRT initial conditions and compute the rapidity and centrality dependence of the charged hadron multiplicities and elliptic flow for LHC <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Pb</mi><mo>+</mo><mi>Pb</mi></mrow></math> and RHIC <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions using <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>(</mo><mn>3</mn><mo>+</mo><mn>1</mn><mo>)</mo><mi mathvariant="normal">D</mi></mrow></math> viscous fluid-dynamical evolution. Also event-by-event fluctuations and decorrelations of initial eccentricities are studied. The good agreement with the rapidity-dependent data suggests that the same saturation mechanism that has been very successful in explaining the midrapidity observables works well also at larger rapidities.

Mikko Kuha

Jussi Auvinen

Kari J. Eskola

Henry Hirvonen

Yuuka Kanakubo

Harri Niemi

Monte Carlo event generator MC-EKRT with saturated minijet production for initializing <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mo>(</mo><mn>3</mn><mo>+</mo><mn>1</mn><mo>)</mo><mi mathvariant="normal">D</mi></mrow></math> fluid dynamics in high-energy nuclear collisions

The nuclear modification factor (<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mi>AA</mi></msub></math>) of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons in high-energy nuclear collisions provides a novel probe of heavy quark interactions with the quark-gluon plasma (QGP). Based on a linear Boltzmann transport model that incorporates both Yukawa and string types of interactions between heavy quarks and the QGP, we study the production and evolution of heavy quarks and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons within the same framework. A <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> bound state dissociates while one of its constituent heavy quarks scatters with the QGP with momentum transfer greater than its binding energy. The medium-modified charm and bottom quarks can recombine into <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons, and the medium-modified bottom quarks can also fragment to <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons. We find that most primordial <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons generated from the initial hard collisions dissociate inside the QGP. The production of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons is primarily driven by the recombination mechanism at low transverse momentum and fragmentation at high transverse momentum. The string interaction dominates over the Yukawa interaction in the nuclear modification of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons. The participant number dependence of the <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> meson <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mi>AA</mi></msub></math> is determined by the complicated interplay between the heavy quark yield, energy loss, and the QGP volume. We obtain a reasonable description of the <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>R</mi><mi>AA</mi></msub></math> of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Pb</mi><mo>+</mo><mi>Pb</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mi>NN</mi></msub></msqrt><mo>=</mo><mn>5.02</mn></mrow></math> TeV, and provide predictions for <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msqrt><msub><mi>s</mi><mi>NN</mi></msub></msqrt><mo>=</mo><mn>200</mn></mrow></math> GeV.

Lejing Zhang

Xiaowen Li

Wen-Jing Xing

Shanshan Cao

Guang-You Qin

Nuclear modification of <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>B</mi><mi>c</mi></msub></math> mesons in relativistic heavy-ion collisions based on a linear Boltzmann transport model

The JETSCAPE Collaboration reports a new determination of the jet transport parameter <math xmlns="http://www.w3.org/1998/Math/MathML"><mover accent="true"><mi>q</mi><mo>̂</mo></mover></math> in the quark-gluon plasma (QGP) using Bayesian inference, incorporating all available inclusive hadron and jet yield suppression data measured in heavy-ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). This multi-observable analysis extends the previously published JETSCAPE Bayesian inference determination of <math xmlns="http://www.w3.org/1998/Math/MathML"><mover accent="true"><mi>q</mi><mo>̂</mo></mover></math>, which was based solely on a selection of inclusive hadron suppression data. jetscape is a modular framework incorporating detailed dynamical models of QGP formation and evolution, and jet propagation and interaction in the QGP. Virtuality-dependent partonic energy loss in the QGP is modeled as a thermalized weakly coupled plasma, with parameters determined from Bayesian calibration using soft-sector observables. This Bayesian calibration of <math xmlns="http://www.w3.org/1998/Math/MathML"><mover accent="true"><mi>q</mi><mo>̂</mo></mover></math> utilizes active learning, a machine-learning approach, for efficient exploitation of computing resources. The experimental data included in this analysis span a broad range in collision energy and centrality, and in transverse momentum. In order to explore the systematic dependence of the extracted parameter posterior distributions, several different calibrations are reported, based on combined jet and hadron data; on jet or hadron data separately; and on restricted kinematic or centrality ranges of the jet and hadron data. Tension is observed in comparison of these variations, providing new insights into the physics of jet transport in the QGP and its theoretical formulation.

J. Mulligan

Bayesian inference analysis of jet quenching using inclusive jet and hadron suppression measurements