Sneha Malde

Abstract:

Particle Identification (PID) is a key requirement for future Higgs factories such as FCC-ee, in particular for heavy-flavour physics and jet flavour tagging. The ARC (Array of RICH Cells) detector is a novel compact and modular RICH (Ring Imaging Cherenkov) concept designed to provide charged hadron separation over a momentum range 1 − 40 GeV/c . ARC combines gas and aerogel radiators within independent cells, each equipped with spherical mirrors and SiPM-based photodetectors. A detailed simulation and reconstruction framework has been developed, including inverse ray-tracing algorithms for Cherenkov angle reconstruction. Simulation studies demonstrate excellent photon yield and π / K separation performance across the target momentum range.

Abstract:

We present a Monte Carlo-based simulation stack that provides time-of-flight (ToF)-resolved blood flow index (BFi) and has been validated against continuous-wave (CW) and time-resolved BFi measurements in both tissue-mimicking phantoms and in-vivo. Using this simulation, we evaluated the influence of key parameters including source-detector separation, ToF selection, and minimum resolvable lag on brain sensitivity by comparing simulated pulsatile blood flow signals from scalp and brain layers. We used these results to optimise the design of CoMind Research One (R1), a 16-channel interferometric time-of-flight-resolved optical neuromonitoring system that operates in real time and enables high-fidelity measurements of field autocorrelation at times-of-flight exceeding 1 ns. We validated this system and demonstrated its depth sensitivity using homogeneous and bi-layer dynamic tissue-mimicking phantoms. The advancements in optical throughput, depth selectivity, and robustness demonstrated by CoMind R1 pave the way for clinical translation and broader adoption of non-invasive optical measurements of cerebral blood flow.

Abstract:

<jats:p>The study of meson pairs produced with quantum correlations gives direct access to parameters that are challenging to measure in other systems. In this Letter, the existence of quantum correlations due to charge-conjugation symmetry <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>C</a:mi></a:math> are demonstrated in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>D</c:mi><c:mover accent="true"><c:mi>D</c:mi><c:mo stretchy="true">¯</c:mo></c:mover></c:math> pairs produced through the processes <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:msup><g:mi>e</g:mi><g:mo>+</g:mo></g:msup><g:msup><g:mi>e</g:mi><g:mo>−</g:mo></g:msup><g:mo stretchy="false">→</g:mo><g:mrow><g:mi>D</g:mi><g:mover accent="true"><g:mi>D</g:mi><g:mo stretchy="true">¯</g:mo></g:mover></g:mrow></g:math>, <l:math xmlns:l="http://www.w3.org/1998/Math/MathML" display="inline"><l:msup><l:mi>e</l:mi><l:mo>+</l:mo></l:msup><l:msup><l:mi>e</l:mi><l:mo>−</l:mo></l:msup><l:mo stretchy="false">→</l:mo><l:mrow><l:msup><l:mi>D</l:mi><l:mo>*</l:mo></l:msup><l:mover accent="true"><l:mi>D</l:mi><l:mo stretchy="true">¯</l:mo></l:mover></l:mrow></l:math>, and <q:math xmlns:q="http://www.w3.org/1998/Math/MathML" display="inline"><q:msup><q:mi>e</q:mi><q:mo>+</q:mo></q:msup><q:msup><q:mi>e</q:mi><q:mo>−</q:mo></q:msup><q:mo stretchy="false">→</q:mo><q:mrow><q:msup><q:mi>D</q:mi><q:mo>*</q:mo></q:msup><q:mrow><q:msup><q:mover accent="true"><q:mi>D</q:mi><q:mo stretchy="true">¯</q:mo></q:mover><q:mo>*</q:mo></q:msup></q:mrow></q:mrow></q:math>, where the lack of charge superscripts refers to an admixture of neutral-charm-meson particle and antiparticle states, using <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"><v:mn>7.13</v:mn><v:mtext> </v:mtext><v:mtext> </v:mtext><v:msup><v:mi>fb</v:mi><v:mrow><v:mo>−</v:mo><v:mn>1</v:mn></v:mrow></v:msup></v:math> of <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"><x:msup><x:mi>e</x:mi><x:mo>+</x:mo></x:msup><x:msup><x:mi>e</x:mi><x:mo>−</x:mo></x:msup></x:math> collision data collected by the BESIII experiment between center-of-mass energies of 4.13–4.23 GeV. Processes with either <z:math xmlns:z="http://www.w3.org/1998/Math/MathML" display="inline"><z:mi>C</z:mi></z:math>-even or <bb:math xmlns:bb="http://www.w3.org/1998/Math/MathML" display="inline"><bb:mi>C</bb:mi></bb:math>-odd constraints are identified and separated. A procedure is presented that harnesses the entangled production process to enable measurements of <db:math xmlns:db="http://www.w3.org/1998/Math/MathML" display="inline"><db:msup><db:mi>D</db:mi><db:mn>0</db:mn></db:msup></db:math>-meson hadronic parameters. This Letter provides the first confirmation of quantum correlations in <fb:math xmlns:fb="http://www.w3.org/1998/Math/MathML" display="inline"><fb:msup><fb:mi>e</fb:mi><fb:mo>+</fb:mo></fb:msup><fb:msup><fb:mi>e</fb:mi><fb:mo>−</fb:mo></fb:msup><fb:mo stretchy="false">→</fb:mo><fb:mi>X</fb:mi><fb:mrow><fb:mi>D</fb:mi><fb:mover accent="true"><fb:mi>D</fb:mi><fb:mo stretchy="true">¯</fb:mo></fb:mover></fb:mrow></fb:math> processes and the first observation of a <kb:math xmlns:kb="http://www.w3.org/1998/Math/MathML" display="inline"><kb:mi>C</kb:mi></kb:math>-even constrained <mb:math xmlns:mb="http://www.w3.org/1998/Math/MathML" display="inline"><mb:mi>D</mb:mi><mb:mover accent="true"><mb:mi>D</mb:mi><mb:mo stretchy="true">¯</mb:mo></mb:mover></mb:math> system. The procedure is applied to measure <qb:math xmlns:qb="http://www.w3.org/1998/Math/MathML" display="inline"><qb:msubsup><qb:mi>δ</qb:mi><qb:mrow><qb:mi>K</qb:mi><qb:mi>π</qb:mi></qb:mrow><qb:mi>D</qb:mi></qb:msubsup></qb:math>, the strong phase between the <sb:math xmlns:sb="http://www.w3.org/1998/Math/MathML" display="inline"><sb:mrow><sb:msup><sb:mrow><sb:mi>D</sb:mi></sb:mrow><sb:mrow><sb:mn>0</sb:mn></sb:mrow></sb:msup><sb:mo stretchy="false">→</sb:mo><sb:msup><sb:mrow><sb:mi>K</sb:mi></sb:mrow><sb:mrow><sb:mo>−</sb:mo></sb:mrow></sb:msup><sb:msup><sb:mrow><sb:mi>π</sb:mi></sb:mrow><sb:mrow><sb:mo>+</sb:mo></sb:mrow></sb:msup></sb:mrow></sb:math> and <vb:math xmlns:vb="http://www.w3.org/1998/Math/MathML" display="inline"><vb:mrow><vb:mrow><vb:msup><vb:mrow><vb:mover accent="true"><vb:mrow><vb:mi>D</vb:mi></vb:mrow><vb:mrow><vb:mo stretchy="true">¯</vb:mo></vb:mrow></vb:mover></vb:mrow><vb:mrow><vb:mn>0</vb:mn></vb:mrow></vb:msup></vb:mrow><vb:mo stretchy="false">→</vb:mo><vb:msup><vb:mrow><vb:mi>K</vb:mi></vb:mrow><vb:mrow><vb:mo>−</vb:mo></vb:mrow></vb:msup><vb:msup><vb:mrow><vb:mi>π</vb:mi></vb:mrow><vb:mrow><vb:mo>+</vb:mo></vb:mrow></vb:msup></vb:mrow></vb:math> decay amplitudes, which results in the determination of <ac:math xmlns:ac="http://www.w3.org/1998/Math/MathML" display="inline"><ac:mrow><ac:msubsup><ac:mrow><ac:mi>δ</ac:mi></ac:mrow><ac:mrow><ac:mi>K</ac:mi><ac:mi>π</ac:mi></ac:mrow><ac:mrow><ac:mi>D</ac:mi></ac:mrow></ac:msubsup><ac:mo>=</ac:mo><ac:mo stretchy="false">(</ac:mo><ac:msubsup><ac:mrow><ac:mn>192.8</ac:mn></ac:mrow><ac:mrow><ac:mo>−</ac:mo><ac:mn>12.4</ac:mn><ac:mo>−</ac:mo><ac:mn>2.4</ac:mn></ac:mrow><ac:mrow><ac:mo>+</ac:mo><ac:mn>11.0</ac:mn><ac:mo>+</ac:mo><ac:mn>1.9</ac:mn></ac:mrow></ac:msubsup><ac:mo stretchy="false">)</ac:mo><ac:mo>°</ac:mo></ac:mrow></ac:math>. The potential for measurements of other hadronic decay parameters and charm mixing with these and future datasets is also discussed.</jats:p>

Abstract:

<jats:p>A novel measurement technique of strong-phase differences between the decay amplitudes of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>D</a:mi><a:mn>0</a:mn></a:msup></a:math> and <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:msup><c:mrow><c:mover accent="true"><c:mrow><c:mi>D</c:mi></c:mrow><c:mrow><c:mo accent="true" stretchy="true">¯</c:mo></c:mrow></c:mover></c:mrow><c:mrow><c:mn>0</c:mn></c:mrow></c:msup></c:mrow></c:math> mesons is introduced which exploits quantum-correlated <h:math xmlns:h="http://www.w3.org/1998/Math/MathML" display="inline"><h:mrow><h:mi>D</h:mi><h:mrow><h:mover accent="true"><h:mrow><h:mi>D</h:mi></h:mrow><h:mrow><h:mo stretchy="true">¯</h:mo></h:mrow></h:mover></h:mrow></h:mrow></h:math> pairs produced by <l:math xmlns:l="http://www.w3.org/1998/Math/MathML" display="inline"><l:msup><l:mi>e</l:mi><l:mo>+</l:mo></l:msup><l:msup><l:mi>e</l:mi><l:mo>−</l:mo></l:msup></l:math> collisions at energies above the <n:math xmlns:n="http://www.w3.org/1998/Math/MathML" display="inline"><n:mi>ψ</n:mi><n:mo stretchy="false">(</n:mo><n:mn>3770</n:mn><n:mo stretchy="false">)</n:mo></n:math> production threshold, where <r:math xmlns:r="http://www.w3.org/1998/Math/MathML" display="inline"><r:mrow><r:mi>D</r:mi><r:mover accent="true"><r:mrow><r:mi>D</r:mi></r:mrow><r:mrow><r:mo stretchy="true">¯</r:mo></r:mrow></r:mover></r:mrow></r:math> pairs are produced in both even and odd eigenstates of the charge-conjugation symmetry. Employing this technique, the first determination of a <v:math xmlns:v="http://www.w3.org/1998/Math/MathML" display="inline"><v:mrow><v:msup><v:mrow><v:mi>D</v:mi></v:mrow><v:mrow><v:mn>0</v:mn></v:mrow></v:msup><v:mi>–</v:mi><v:msup><v:mrow><v:mover accent="true"><v:mrow><v:mi>D</v:mi></v:mrow><v:mrow><v:mo accent="true" stretchy="true">¯</v:mo></v:mrow></v:mover></v:mrow><v:mrow><v:mn>0</v:mn></v:mrow></v:msup></v:mrow></v:math> relative strong phase is reported with such data samples. The strong-phase difference between <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"><ab:mrow><ab:msup><ab:mrow><ab:mi>D</ab:mi></ab:mrow><ab:mrow><ab:mn>0</ab:mn></ab:mrow></ab:msup><ab:mo stretchy="false">→</ab:mo><ab:msup><ab:mrow><ab:mi>K</ab:mi></ab:mrow><ab:mrow><ab:mo>−</ab:mo></ab:mrow></ab:msup><ab:msup><ab:mrow><ab:mi>π</ab:mi></ab:mrow><ab:mrow><ab:mo>+</ab:mo></ab:mrow></ab:msup></ab:mrow></ab:math> and <db:math xmlns:db="http://www.w3.org/1998/Math/MathML" display="inline"><db:mrow><db:msup><db:mrow><db:mover accent="true"><db:mrow><db:mi>D</db:mi></db:mrow><db:mrow><db:mo accent="true" stretchy="true">¯</db:mo></db:mrow></db:mover></db:mrow><db:mrow><db:mn>0</db:mn></db:mrow></db:msup><db:mo stretchy="false">→</db:mo><db:msup><db:mrow><db:mi>K</db:mi></db:mrow><db:mrow><db:mo>−</db:mo></db:mrow></db:msup><db:msup><db:mrow><db:mi>π</db:mi></db:mrow><db:mrow><db:mo>+</db:mo></db:mrow></db:msup></db:mrow></db:math> decays, <jb:math xmlns:jb="http://www.w3.org/1998/Math/MathML" display="inline"><jb:msubsup><jb:mi>δ</jb:mi><jb:mrow><jb:mi>K</jb:mi><jb:mi>π</jb:mi></jb:mrow><jb:mi>D</jb:mi></jb:msubsup></jb:math>, is measured to be <lb:math xmlns:lb="http://www.w3.org/1998/Math/MathML" display="inline"><lb:msubsup><lb:mi>δ</lb:mi><lb:mrow><lb:mi>K</lb:mi><lb:mi>π</lb:mi></lb:mrow><lb:mi>D</lb:mi></lb:msubsup><lb:mo>=</lb:mo><lb:msup><lb:mrow><lb:mo stretchy="false">(</lb:mo><lb:msubsup><lb:mn>192.8</lb:mn><lb:mrow><lb:mo>−</lb:mo><lb:mn>12.4</lb:mn><lb:mo>−</lb:mo><lb:mn>2.4</lb:mn></lb:mrow><lb:mrow><lb:mo>+</lb:mo><lb:mn>11.0</lb:mn><lb:mo>+</lb:mo><lb:mn>1.9</lb:mn></lb:mrow></lb:msubsup><lb:mo stretchy="false">)</lb:mo></lb:mrow><lb:mo>∘</lb:mo></lb:msup></lb:math>, using a dataset corresponding to an integrated luminosity of <pb:math xmlns:pb="http://www.w3.org/1998/Math/MathML" display="inline"><pb:mn>7.13</pb:mn><pb:mtext> </pb:mtext><pb:mtext> </pb:mtext><pb:msup><pb:mi>fb</pb:mi><pb:mrow><pb:mo>−</pb:mo><pb:mn>1</pb:mn></pb:mrow></pb:msup></pb:math> collected at center-of-mass energies between 4.13–4.23 GeV by the BESIII experiment.</jats:p>

Abstract:

Using (2712 ± 14) × 106ψ(3686) events collected with the BESIII detector, we perform the first amplitude analysis of the radiative decay ψ3686→γKS0KS0$$ \psi (3686)\to \gamma {K}_S^0{K}_S^0 $$ within the mass region MKS0KS0<2.8$$ {M}_{K_S^0{K}_S^0}<2.8 $$ GeV/c2. Employing a one-channel K-matrix approach for the description of the dynamics of the KS0KS0$$ {K}_S^0{K}_S^0 $$ system, the data sample is well described with four poles for the f0-wave and three poles for the f2-wave. The determined pole positions are consistent with those of well-established resonance states. The observed f0 and f2 states are found to be in agreement with those produced in radiative J/ψ decays. The production behaviors of f0 and f2 poles in ψ3686→γKS0KS0$$ \psi (3686)\to \gamma {K}_S^0{K}_S^0 $$ are qualified with their residues and the converted branching fractions. By comparing with J/ψ→γKS0KS0$$ J/\psi \to \gamma {K}_S^0{K}_S^0 $$ decay, the ratios Bψ3686→γf0,2BJ/ψ→γf0,2$$ \frac{\mathcal{B}\left(\psi (3686)\to \gamma {f}_{0,2}\right)}{\mathcal{B}\left(J/\psi \to \gamma {f}_{0,2}\right)} $$ are determined, which provides crucial experimental inputs on the internal structure of the f0,2 states, especially their potential mixing with glueball components.