Himanshu Sharma

Postdoctoral researcher in experimental high-energy nuclear physics

INFN Fellow and member of the ALICE Collaboration at CERN.
Istituto Nazionale di Fisica Nucleare (INFN), Section of Padova, Italy.

Download CV (PDF) himanshu.sharma@cern.ch

Schematic transverse view of a heavy-ion collision: many tracks leave the primary vertex, and three highlighted tracks come from a charm baryon that decayed a short distance away.
Schematic transverse view of a collision, not to scale. The highlighted tracks come from a charm baryon that decayed a fraction of a millimeter from the primary vertex.

Profile

Postdoctoral researcher in experimental high-energy nuclear physics (ALICE Collaboration at CERN) specializing in charmonium production, heavy-flavor hadronization, and machine learning applications for science and physics experiments. Proven track record in leading complex data analyses, calibrating detector simulations, and developing machine learning methods for physics data analysis, simulation, and detector performance. Serving on international collaboration review committees, and recognized for providing high-precision measurements that test and constrain QCD models, supported by an active portfolio in university-level lecturing, student mentorship, and science communication.

KeywordsStrong interactions, quantum chromodynamics (QCD), quark–gluon plasma (QGP), high-energy nuclear collisions, charmonium and heavy-flavor production, machine learning applications.

Himanshu Sharma

Research and education

Feb 2023 –
present

Postdoctoral researcher, ALICE experiment

Istituto Nazionale di Fisica Nucleare (INFN), Padova, Italy

The contract began on 6 February 2023, during the final thesis-writing phase of the PhD. The doctoral degree was awarded on 4 December 2023.

Physics measurements

  • Charm-strange baryon (Ξ+c) production in pp and Pb–Pb collisions in LHC Run 3 (2022–26), using machine learning techniques.
    • Machine learning-based signal selection. Extracted the invariant-mass signals of Ξ+c → pK−π+ and Λ+c → pK−π+ with Boosted Decision Trees (BDTs) to optimize signal-to-background separation, particularly in the low-transverse-momentum region, in pp collisions.
    • Physics analysis and dissemination. Measured the charm baryon-to-baryon ratio Ξ+c/Λ+c in pp collisions at √s = 13.6 TeV, compared the results with theoretical QCD models, and presented these findings for the first time in two talks (Talk 1, Talk 2) at the SQM 2026 conference.

Software development

  • Software tools for data-driven calibration of Monte Carlo simulations.
    • Main developer of the software implementation of a method that modifies the spatial and momentum resolutions of reconstructed tracks in the simulation to reproduce those estimated in data with data-driven techniques. The approach has since been adopted in multiple ALICE heavy-flavor analyses to help reduce systematic uncertainties. This is crucial for the measurements of all hadrons decaying far from the primary vertex, especially hadrons containing charm or beauty quarks.

Oct 2018 –
Dec 2023

Doctoral researcher, ALICE experiment

Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Kraków, Poland

PhD in high-energy nuclear physics. Advisor: Dr. hab. Jacek Otwinowski. Thesis defended on 24 November 2023, degree awarded on 4 December 2023.

Thesis: “Prompt and non-prompt J/ψ production in Pb–Pb collisions at √sNN = 5.02 TeV with ALICE experiment”

Physics measurements

  • Prompt and non-prompt J/ψ production in Pb–Pb collisions at √sNN = 5.02 TeV in the ALICE experiment.
    • Extraction of non-prompt J/ψ fractions using two-dimensional simultaneous likelihood fits on the invariant mass and decay length of J/ψ candidates, reconstructed via the J/ψ → e+e− decay channel at midrapidity using datasets collected during LHC Run 2.
    • Determination of nuclear modification factors and production yields of prompt and non-prompt J/ψ as a function of transverse momentum and collision centrality.

Detector development

  • Contribution to the development of the ALICE Fast Interaction Trigger (FIT) detector for LHC Run 3 during Long Shutdown 2 (LS2).
    • Tested the signal and high-voltage setup for all channels of the FIT-FT0 detector. Also contributed to detector commissioning, taking part in cosmic-ray data taking and data analysis.
    • Tested the performance of FIT-FV0 detector channels with laser signals after commissioning at the LHC, CERN (Link 1, Link 2).
    • FIT software: developed time-calibration tasks in the Quality Control framework for the FV0 detector (PR), and tested time calibration for FV0 channels with laser and simulation data (Link).

Jul –
Oct 2018

Research assistant

Indian Institute of Technology (IIT) Indore, India

  • Investigated freeze-out temperatures and radial flow in proton–proton collisions at √s = 7 TeV by analyzing the transverse-momentum spectra of produced charged and strange hadrons.
  • Acquired expertise in thermodynamic modeling (Blast-Wave models and Tsallis statistics) to extract key thermodynamic parameters and describe the collective expansion of the system.

Aug 2016 –
Jul 2018

M.Sc. Physics

Indian Institute of Technology (IIT) Madras, India

Thesis: “Elliptic flow of charged hadrons in Pb–Pb collisions at √sNN = 2.76 TeV using the AMPT”. Advisor: Dr. Prabhat Pujahari.

  • Studied the collective behavior of the hot, dense medium produced in Pb–Pb collisions at √sNN = 2.76 TeV by analyzing azimuthal anisotropy observables using the AMPT event generator.
  • Acquired expertise in heavy-ion event generators, relativistic kinematics, and heavy-ion phenomenology, with a focus on characterizing elliptic flow as a smoking-gun signature of QGP formation.

Aug 2012 –
Aug 2015

B.Sc.

University of Kota, India

Publications

As a member of the ALICE Collaboration I am a co-author of more than 250 publications. The complete list is on my INSPIRE-HEP profile.

Journal articles

2024

Prompt and non-prompt J/ψ production at midrapidity in Pb–Pb collisions at √sNN = 5.02 TeV

ALICE Collaboration, JHEP 02 (2024) 066. Main analyzer and paper committee member.

2019

Conference proceedings

Written for the ALICE Collaboration, unless noted.

2018

An overview of differential freeze-out and radial flow in pp collisions at √s = 7 TeV at the LHC

DAE Symp. Nucl. Phys. 63 (2018) 982–983. Co-author and analyzer.

Conference presentations

Parallel talks

2026

Testing pQCD calculations and hadronisation with charm and beauty hadrons in pp collisions with ALICE

International Conference on High Energy Physics (ICHEP) 2026, Natal, Brazil, 31 Jul – 5 Aug 2026

2025

Studying charm-quark hadronization via charm-baryon production measurements in pp at the LHC with ALICE

Quark Matter (QM) 2025, Frankfurt, Germany, 6–⁠12 April 2025

2024

D*+ spin alignment in ultrarelativistic heavy ion collisions in ALICE

Strangeness in Quark Matter (SQM) 2024, Strasbourg, France, 3–⁠7 May 2024

2023

Recent charmonium measurements in Pb–Pb collisions with ALICE

European Physical Society High Energy Physics (EPS-HEP) Conference 2023, Hamburg, Germany, 21–⁠25 Aug 2023

2022

Prompt, non-prompt, and coherent J/ψ production in Pb–Pb collisions with ALICE

EMMI Conference 2022, Kraków, Poland, 19–⁠22 Sept 2022

2022

Inclusive, prompt, and non-prompt J/ψ production at midrapidity in Pb–Pb collisions at 5.02 TeV with ALICE

International Conference on High Energy Physics (ICHEP) 2022, Bologna, Italy, 6–⁠13 July 2022

2022

Charmonium as a probe of hot quark matter in nuclear collisions in ALICE at the LHC

Epiphany 2022, Kraków, Poland, 10–⁠14 Jan 2022 (online), student session

2021

Beauty production in pp and Pb–Pb collisions with ALICE

MESON 2021, 17–⁠21 May 2021 (online)

Posters

2022

Prompt and non-prompt J/ψ production at midrapidity in Pb–Pb collisions at 5.02 TeV with ALICE

Large Hadron Collider Physics Conference (LHCP) 2022, 16–⁠20 May 2022 (online)

2021

Non-prompt J/ψ measurements at midrapidity in pp, p–Pb and Pb–Pb collisions with ALICE

Particles and Nuclei Conference (PANIC) 2021, 5–⁠10 Sept 2021 (online)

2021

Measurements of non-prompt J/ψ-meson at midrapidity in Pb–Pb collisions with ALICE at the LHC

Initial Stages (IS) Conference 2021, 10–⁠15 January 2021 (online)

Roles in the ALICE Collaboration

Internal and analysis review committees

Reviewing ALICE paper drafts, checking the consistency of the analysis procedure, and suggesting improvements to the quality of the measurements.

IRC member

Multiplicity-dependent Ξ+c and Ξ0c production in pp collisions at √s = 13 TeV (submitted to JHEP)

ARC member

Measurement of D*+ spin alignment in pp collisions at √s = 13.6 TeV

ARC member

Double charm production measurements: D0–J/ψ associated production and D0–D0 production in pp collisions at √s = 13.6 TeV

ARC member

Lifetime measurements of Λ+c and Ω0c baryons in pp collisions at √s = 13.6 TeV

Referee

External journal peer review for the Turkish Journal of Physics (TÜBİTAK)

Detector operations and data taking

Mar – Apr 2024

Shift Leader and Detector Control System (DCS) shifter. Managed real-time detector operations, safety protocols, and data-taking quality control during active LHC runs.

Jul 2023

Data Quality Control (QC) shifter. Monitored live data streams to identify, troubleshoot, and document detector anomalies, ensuring high-quality data preservation.

Data quality and software contributions

Feb – Dec 2023

Global track quality monitoring in reconstructed data. Systematic evaluation of global track reconstruction quality in reconstructed datasets from pp and Pb–Pb collisions. Processed large-scale data samples and presented weekly quality control assessments at ALICE QA collaboration meetings.

Jan – Dec 2024

Track impact parameter performance. Evaluated and monitored track impact parameter performance across LHC Run 3 datasets (pp and Pb–Pb collisions). Conducted comparative studies between data and anchored Monte Carlo simulations, presented regularly in internal ALICE working groups.

Ongoing

Monte Carlo simulation tuning (ALICE Padova group). Developed and implemented data-driven parametrizations to tune impact parameter distributions in Monte Carlo simulations, significantly improving simulation-to-data agreement for the collaboration.

Funding and awards

Fellowships and grants

2025 – 2027

INFN Postdoctoral Research Fellowship, INFN Section of Padova, Italy (2 years, total 77,447 EUR)

2023 – 2025

Postdoctoral Research Grant (INFN & STRONG-2020), INFN Padova, Italy (24 months)

2023

Postdoctoral Research Grant, University of Padova, Italy (4 months, total 5,600 EUR)

2023

CNRS Postdoctoral Fellowship, IJCLab, University of Paris-Saclay, France (declined)

2018 – 2022

Doctoral Fellowship, Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN)

Jan 2022

NAWA Student Exchange Grant, University and INFN Section of Cagliari, Italy (2-week scientific visit, 10,000 PLN / ~2,500 EUR)

Awards and qualifications

2024

INFN Fellowship Award, ranked 3rd globally (score 95.7%). Awarded the Senior Level 3 Research Grant in Experimental Physics. Only 20 recipients are selected annually worldwide across experimental particle, nuclear, astroparticle physics, and technological research.

2016

Top 1% national rank, IIT-JAM. Secured All India Rank 195 out of thousands of candidates in the highly competitive national entrance examination for the M.Sc. in Physics.

2016, 2018

National research eligibility qualifications (India). Qualified in the Joint Entrance Screening Test (JEST-2016) and the Graduate Aptitude Test in Engineering (GATE-2018).

Teaching and mentoring

Student Lectures Assitance

Erasmus Mundus Joint Master’s degree program (NucPhys at UniPd): lectures on “Ultrarelativistic heavy-ion collisions” at the University of Padova.

  • Designed the hands-on sessions for D0-meson yield extraction.
  • Designed and delivered a hands-on lecture on machine learning in heavy-ion collisions.

2021

Co-supervisor. Co-supervised two undergraduate summer students in the IFJ PAN Particle Physics Summer Student Programme (PPSS 2021), in a project on the application of machine learning to J/ψ signal extraction using electron–positron pairs in Pb–Pb collisions in ALICE.

Schools and visits

External training and research visits beyond my home institutions.

2019

Summer school. Selected to attend Machine Learning in High-Energy Physics (MLHEP-2019), DESY, Hamburg, Germany.

Jan 2022

Research visit. 15-day internship at the University and INFN Cagliari, Italy, working on prompt and non-prompt J/ψ measurements in Pb–Pb collisions with Dr. Fiorella Fionda (Physics Working Group convener in ALICE).

Writing and outreach

Science communication on Medium, on physics, mathematics, and artificial intelligence.

Hand-picked and “Boosted” by the Medium curator team: distributed across 11,000+ feeds, with 500+ views and 200+ reads.

Public outreach

2018 – 2022

Exhibitor, Małopolska Researchers’ Night, Kraków, Poland. Every September for four years. Designed and built a portable DIY cloud chamber for real-time tracking and demonstration of cosmic radiation to the general public (experimental tracking video).

Professional skills

Programming
C, C++, Python (including data visualization), bash scripting
Machine learning
Boosted Decision Trees (BDTs), multilayer perceptrons and neural networks, deep learning applications
Simulation
Heavy-ion simulations with the AMPT event generator
Analysis and tools
HEP data analysis with ROOT and RooFit, GitHub, LaTeX

Projects

ML+QGPHydro

FNO surrogate for viscous QGP hydrodynamics

Fourier Neural Operator trained on vHLLE viscous hydro events to replace the slow hydrodynamic evolution step in Pb–Pb event generation at √sNN = 5.36 TeV. Achieves ~200× GPU speedup (GitHub).

Playground

Small interactive science-education demos, made for fun and public engagement. More to come.

Play

Buffon's Needle

An interactive take on Buffon's needle problem: drop needles on a lined floor and watch a simple probability experiment close in on π.

Visualize!

Quark-gluon plasma and its evolution

Rotate a quark-gluon plasma fireball in Pb–Pb collisions at √sNN = 5.36 TeV. Shows the ~65,000 irregular Cornelius freeze-out cells and the 61×61 FNO surrogate grid — the geometry behind elliptic flow v2. Part of the FNO_Hydro surrogate project.

Play

Collidoscope

A kaleidoscope: click to drop shapes, scatter at random, and rotate to see new mirrored, symmetric patterns.

Play

DigitWalker

Numbers go for a walk: each digit is a step, and the path turns after every step. Compare π, √2 or 1/7 and see how rational and irrational numbers behave.