About

This is the official website for the ERC-funded ASYMOW project. The main deliverable of the ASYMOW project is the measurement of the W boson mass with the CMS detector using a novel analysys technique and an unprecedented amount of LHC data.

Despite its success in describing the sub-nuclear realm, the Standard Model of particle and field interactions cannot account for a number of experimental facts that constitute evidence of new and unknown physics. Sitting at both the energy and intensity frontier, the LHC grants the highest chances for solving the current puzzle. By exploiting the data collected by the CMS experiment at the LHC, ASYMOW aims at attaining an unprecedented experimental accuracy on a fundamental parameter of Nature: the mass of the W boson. There is a tension between the Standard Model expectation and the measured value of the W boson mass according to the recent CDF-II result. A new measurement with a 10 MeV uncertainty is a breakthrough: it could either rule out the tension or build a convincing case that this anomaly is real, thus implying the existence of new physics. The collider physics community has been pursuing this goal for decades. The quest now seems to have hit the wall of systematic uncertainty. This project proposes a new approach towards the W boson mass measurement, which will circumvent the systematic uncertainties that are currently limiting the precision. The novelty of the proposed method lies in its agnosticism with respect to the microscopic picture of W boson production in hadron collisions. The loss of prior knowledge inherent to this new approach will be asymptotically compensated by the large amount of data available for the measurement, as will be collected at the LHC.

ASYMOW will be conducted by a small group of scientists and comes with great experimental and theoretical challenges. The main expected result is the measurement of the W boson mass with a precision better than the state-of-the-art. This may open new scenarios in particle physics.

Recently the CMS experiment published its first measurement of the W boson mass, with contributions from the ASYMOW team. The CMS result has a precision similar to that of CDF-II, however it is in agreement with the Standard Model expectation. A new measurement from CMS using the novel approach proposed by the ASYMOW project would continue to shed light on the "W mass puzzle".

Overview of measurements of the W boson mass; the recent CMS result is shown in red. Ref: arXiv:2412.13872

Conference talks

  1. L. Bianchini, "Measuring MW at the LHC", Collider Cross Talk, CERN, 23-06-2022, link
  2. L. Bianchini, "Precision Measurement of the W boson mass: status and prospects", invited talk at "LFC22: Strong interactions from QCD to new strong dynamics at LHC and Future Colliders", ECT*, Trento, 02-09-2022, link
  3. D. Bruschini, "Comparison of track properties between Data and MC at CMS using early Run-3 data", 109 Congresso Nazionale SIF, Milano, 13-09-2022, link
  4. D. Bruschini, "Comparison of track properties between Data and MC at CMS using early Run-3 data", Students’ poster session at the 152nd LHCC meeting, CERN, 22-11-2022, link
  5. T. Sarkar, "W mass discussion: the theory agnostic fit", PhysTeV @ Les Houches 2023, 13-06-2023, link
  6. M. Musich, "Performance of the CMS Tracker in Run 3", ICNFP2023: 12th International Conference on New Frontiers in Physics, 18-07-2023, link
  7. M. Musich, "Present and future of tracking and vertexing in CMS", TIPP2023: 6th International conference on Technology and Instrumentation in Particle Physics, 04-09-2023 link
  8. C. Alexe, "Data-driven performance of muon momentum scale at CMS using the Z boson mass as a standard candle", 110 Congresso Nazionale SIF, Salerno, 14-09-2023, link
  9. R. Bhattacharya, "Performance of the muon object during the 2022 data-taking period of CMS", 110 Congresso Nazionale SIF, Salerno, 14-09-2023, link
  10. M. Musich, "Tracking, vertexing and b-tagging at the LHC", Vertex2023: 32nd International Workshop on Vertex Detectors, 16-10-2023, link
  11. D. Bruschini, "Performance e nuovi sviluppi nella ricostruzione delle tracce in CMS durante il Run 3", Incontri di Fisica delle Alte Energie 2024 (IFAE 2024), Firenze, 04-04-2024, link
  12. M. Cipriani, "Precision measurements with W boson decays at LHC (ATLAS,CMS and LHCb)", SM@LHC Workshop 2024, Rome, 07-05-2024, link
  13. M. Musich, "Performance hightlights in CMS", 12th Edition of the Large Hadron Collider Physics Conference, Boston, 04-06-2024, link
  14. D. Bruschini, "CMS track reconstruction performance and tracking developments during Run 3", 42nd International Conference on High Energy Physics (ICHEP 2024), Prague, 19-07-2024, link
  15. C. Alexe, "Electroweak measurements in CMS", XIII International Conference on New Frontiers in Physics 2024, Kolymbari (Crete), 28-08-2024, link
  16. M. Musich, "Tracking and vertexing in CMS", FTAG2024: 2024 ATLAS-CMS Flavour Tagging Workshop, Genova, 09-09-2024, link
  17. C. Alexe, "Error underestimation in high-statistics counting experiments with finite Monte Carlo samples", Poster session at the 2nd ECFA-INFN Early Career Researchers Meeting, Rome, 01-10-2024, link
  18. T. Sarkar, "Precision measurements of W-boson mass", The Fifteenth Particle Physics Phenomenology Workshop (PPP15), Tapei City, 21-10-2024, link
  19. D. Bruschini, "High-precision measurement of the W boson mass at CMS", Blois 2024: 35th Rencontres de Blois on "Particle Physics and Cosmology", Gaston d'Orléans, 22-10-2024, link
  20. R. Bhattacharya, "Measurement of the W boson mass at CMS", The 43rd International Symposium on Physics in Collision - PIC 2024, Athens, 23-10-2024, link
  21. D. Bruschini, "W-boson mass measurement at CMS: high-precision determination of muon reconstruction and identification efficiencies", Students’ poster session at the 160th LHCC meeting, CERN, 18-11-2024, link
  22. M. Musich, "Description and performance of the current CMS trigger", TDIII-2024: Triggering Discoveries in High Energy Physics III, Vysoke Tatry, Slovakia, 11-12-2024, link
  23. C. Alexe, "Subatomic particles: puzzle pieces of the Universe", invited outreach talk at C.N. Mihai Eminescu, Buzau (Romania), 17-12-2024, link

Seminars

  1. L. Bianchini, "New ideas for a precision measurement of the W boson mass at the LHC", invited seminar at Department of Physics, University of Pisa, 10-02-2021, link
  2. L. Bianchini, "New ideas for a precision measurement of the W boson mass", invited seminar at Department of Physics, University of Genova, 07-04-2021, link
  3. L. Bianchini, "Measuring the mass of the W boson: a quest for precision", invited seminar at "Phd Colloquia" series, Department of Physics, University of Pavia, 14-03-2024, link
  4. L. Bianchini, "A measurement of the W boson mass at CMS", invited seminar at Department of Physics, University of Pisa, 26-09-2024, link
  5. M. Cipriani, "Recent results on the W boson mass measurement", invited seminar at Department of Physics, Sapienza Universita' di Roma, 28-10-2024, link
  6. L. Bianchini, "A measurement of the W boson mass at CMS", invited seminar at the INFN Directorate, Sapienza Universita' di Roma, 25-10-2024, link
  7. M. Cipriani, "Measurement of the W boson mass with the CMS experiment", invited seminar at Department of Physics, University of Turin, 14-11-2024, link
  8. L. Bianchini, "A measurement of the W boson mass at CMS", invited seminar at the INFN CSN1 meeting, Venice, 25-11-2024, link
  9. L. Bianchini, "New measurement of the W boson mass at CMS", invited PRISMA+ Colloquium at the Johannes Gutenberg-Universität, Mainz, 27-11-2024, link
  10. L. Bianchini, "A measurement of the W boson mass at CMS", invited Colloquium at INFN Sezione di Firenze, Sesto Fiorentino, 03-12-2024, link
  11. L. Bianchini, "High-precision measurement of the W boson mass with the CMS experiment", invited seminar at INFN Sezione di Bari, Bari, 28-01-2025, link
  12. M. Cipriani, "Measurement of the W-boson mass at CMS", invited seminar at Department of Physics, University of Pavia, 20-02-2025, link

Main Collaboration talks

  1. L. Bianchini, "Prospects for a mW measurement with Run3", SMP-V Workshop, CERN, 24-04-2022, link
  2. D. Bruschini, "W mass status and prospects", SMP@CMS Italia Workshop, CERN, 19-07-2022, link
  3. L. Bianchini, "Status of W mass in CMS", Annual meeting of the CMS-Italy community, Firenze (IT), 26-09-2022, link
  4. R. Bhattacharya, "Reconstruction efficiencies for the W mass measurement", SMP General Meeting, CERN, 04-10-2022, link
  5. D. Bruschini and M. Musich, "TRK performance checks", PPD Workshop, CERN, 30-11-2022, link
  6. C. Alexe and L. Bianchini, "Future/Ultimate mW Measurements Status/Plans/Discussion", CMS mW Hackathon, MIT (MA, USA), 12-01-2023, link
  7. D. Bruschini, "Efficiencies and Backgrounds Status/Goals/Planning", CMS mW Hackathon, MIT (MA, USA), 13-01-2023, link
  8. M. Musich, "Pattern Recognition & Track Fitting", Tracker Training Days, CERN, 02-03-2023, link
  9. M. Cipriani, "Fakes in single electron and muon final states for W boson measurement", "Deep Dive: fake leptons" Workshop, CERN, 04-04-2023, link
  10. M. Cipriani, "Status report on W mass measurement", Physics Plenary during the CMS Week, Saint-Malo (FR), 17-04-2023, link
  11. M. Musich and S.R. Chowdhury, "Run 3 performance report TRK DPG/POG", PPD General Meeting, CERN, 01-06-2023, link
  12. M. Musich, "Physics Coordination report", Physics Plenary during the CMS Week, CERN, 12-06-2023, link
  13. M. Cipriani, "W boson mass: the road to unblinding", SMP General Meeting during the CMS Week, CERN, 13-06-2023, link
  14. D. Bruschini, "W mass report", Physics Plenary during the CMS Week, CERN, 15-06-2023, link
  15. D. Bruschini, "Ultimate precision for W mass measurement", "Deep Dive: Lepton ID" Workshop, CERN, 21-06-2023, link
  16. L. Bianchini, C. Alexe, "Study on (spurious) constraints in mW analysis", CMS Statistics Committee, CERN, 17-07-2023, link
  17. D. Bruschini, "Tracking performance in Run 3: Comparisons with MC and incoming updates for 2024", CMS Tracker Week, CERN, 17-01-2024, link
  18. M. Musich, "Trigger preparations for 2024", Physics Plenary during the CMS Week, CERN, 7-02-2024, link
  19. M. Cipriani, "W boson mass: status report", SMP Workshop, CERN, 18-06-2024, link
  20. M. Cipriani, "Approval of SMP-23-002: Measurement of the W boson mass", CERN, 04-09-2024, link
  21. D. Bruschini, L. Bianchini, M. Cipriani, "Measurement of the W boson mass at 13 TeV at CMS", Annual Meeting of the CMS-Italy community, Roma, 07-10-2024, link
  22. C. A. Alexe, "Precise calibration of the muon momentum scale for the mW measurement and more", Annual Meeting of the CMS-Italy community, Roma, 07-10-2024, link

Publications

Journal publications

  1. C.-A. ALexe, J. Bendavid, L. Bianchini, D. Bruschini, "Undercoverage in high-statistics counting experiments with finite MC samples", arXiv:2401.10542 (2024)
  2. C. Aime', C.-A. Alexe, R. Bhattacharya, L. Bianchini, D. Bruschini, S.R. Chowdhury, M. Cipriani, M. Musich, T. Sarkar, F. Tenchini et al. [CMS Collaboration], "Measurement of the W boson mass in proton-proton collisions at sqrt(s) = 13 TeV", CMS-PAS-SMP-23-002, arXiv:2412.13872, submitted to Nature
  3. C. Aime', C.-A. Alexe, R. Bhattacharya, L. Bianchini, D. Bruschini, S.R. Chowdhury, M. Cipriani, M. Musich, T. Sarkar, F. Tenchini et al. [CMS Collaboration], "Precise calibration of the muon momentum scale for electroweak precision measurements", MUO-23-001 in preparation
CMS public documents
  1. D. Bruschini et al. [CMS Collaboration], "Early Run 3 tracking performance", CERN-CMS-DP-2022-064 (2022)
  2. D. Bruschini et al. [CMS Collaboration], "CMS tracking performance in 2023", CERN-CMS-DP-2023-090 (2023)
Conference proceedings
  1. L. Bianchini, "Precision Measurement of the W boson mass: status and prospects", Frascati Physics Series Vol. 73 (2022), proceedings to "LFC22: Strong interactions from QCD to new strong dynamics at LHC and Future Colliders", ISBN 978-88-86409-75-9
CMS internal notes (N.B.: these are CMS-notes for internal use only)
  1. C.-A. Alexe, R. Bhattacharya, L. Bianchini, D. Bruschini, S.R. Chowdhury, M. Cipriani, M. Musich, T. Sarkar, F. Tenchini, "Feasibility studies for a theory-agnostic measurement of MW​ with the full Run 2 data (ASYMOW project)", CMS AN-2023/103
  2. C. Aime', C.-A. Alexe, L. Bianchini, M. Cipriani, D. Bruschini, R. Bhattacharya, S.R. Chowdhury, F. Tenchini, M. Musich et al., "Measurement of the W boson mass and W-like measurement of the Z boson mass at 13 TeV", CMS AN-2020/012
  3. L. Bianchini, M. Cipriani, T. Sarkar et al., "Theoretical predictions and Monte Carlo simulation for the W mass measurement", CMS AN-2020/008
  4. M. Musich et al., "High precision calibration of muon momentum scale for measurement of mW", CMS AN-2021/131

Education

This project is proud to contribute to the education of students. We are currently supervising the work of the following PhD students from our host Universities:

  1. Davide Bruschini, PhD student at SNS from 01-11-2021. Expected date of PhD dissertation: Oct. 2025
  2. Cristina Alexe, PhD student at SNS from 01-11-2022. Expected date of PhD dissertation: Oct. 2026
  3. Ruben Forti, PhD student at University of Pisa from 01-11-2023. Expected date of PhD dissertation: Oct. 2026
Past theses:
  1. Mr. Ruben Forti, M.Sc. in Physics at the University of Pisa with the thesis: "Studies of muon reconstruction for a precise measurement of the W boson mass with the CMS experiment". Supervisor: Prof. L. Bianchini. Succesfully defended on 31-10-2023.

Events

Our weekly working meetings on Indico (access restricted!)

We co-organized the first "CMS mW Hackathon" at MIT, Cambridge (MA) 9-13 Jan, 2023, Indico

We are regularly inviting experts to give seminars on topics relevant for our project:

  1. "A CMS measurement of the effective leptonic weak mixing angle at sqrt(s)=13 TeV" (indico) by Dr. Simone Amoroso (DESY), 10-04-2024, Pisa
  2. "Precision measurements of the W-Boson mass and strong coupling constant" (poster) by Dr. Stefano Camarda (CERN), 17-05-2023, Pisa
  3. "MW determination at hadron colliders: a new proposal" (poster) by Prof. Alessandro Vicini (Università degli Studi di Milano), 07-03-2023, Pisa
  4. "High performance for high precision analysis" (poster) by Dr. Joshua Bendavid (MIT), 11-10-2022, Pisa

People

The ASYMOW team (in order of arrival)

  1. Prof. Lorenzo Bianchini, University of Pisa [web site, ORCID, iNSPIRE]
  2. Mr. Davide Bruschini [ORCID], Scuola Normale Superiore
  3. Mrs. Cristina-Andreea Alexe [ORCID], Scuola Normale Superiore
  4. Dr. Marco Cipriani [ORCID], University of Pisa
  5. Dr. Francesco Tenchini [ORCID], University of Pisa
  6. Mr. Ruben Forti [ORCID], University of Pisa (R.F. is a PhD student at UniPi)
  7. Dr. Chiara Aime' [ORCID], University of Pisa
Past members
  1. Dr. Suvankar Roy Chowdhury [ORCID], postdoc at INFN Sezione di Pisa under the project PRIN 2017F28R78 (currently at UPES, India)
  2. Dr. Marco Musich [ORCID], postdoc at University of Pisa from Jan. 2022 to Jan. 2025 (currently LD Staff at CERN).
  3. Dr. Rajarshi Bhattacharya [ORCID], postdoc at INFN Sezione di Pisa from Feb. 2022 to Feb. 2025
  4. Dr. Tanmay Sarkar [ORCID], postdoc at INFN Sezione di Pisa from Feb. 2022 to Feb. 2025
Our code is under developemnt in the erc-asymow github project

Job opportunities

No positions are available at the moment

Past filled positions:

  1. Call for n.1 assistant professor postions (RTDa) at University of Pisa [closed]. Selected: C. Aime'
  2. Call for n.2 assistant professor postions (RTDa) at University of Pisa [closed]. Selected: F. Tenchini and M. Cipriani
  3. Call for n.1 PhD position at SNS [closed]. Selected: C.A. Alexe
  4. Call for n.1 PhD position at SNS [closed]. Selected: D. Bruschini
  5. Call for n.1 postdoctoral fellowship at University of Pisa [closed]. Selected: M. Musich
  6. Call for n.2 postdoctoral positions at INFN Pisa [closed]. Selected: T. Sarkar and R. Bhattacharya

Press

  1. Press release INFN about the ERC funding
  2. Press release University of Pisa about the ERC funding
  3. Press release Scuola Normale Superiore about the ERC funding
  4. Press article La Nazione about the ERC funding
  5. Press release INFN about the CMS measurement (17-09-2024)
  6. Press release ANSA about the CMS measurement (17-09-2024)
  7. Press article Wired.it about the CMS measurement (17-09-2024)
  8. Press release University of Pisa about the CMS measurement (20-09-2024)
  9. Press article QUInews Pisa.it about the CMS measurement (20-09-2024)
  10. Press release Scuola Normale Superiore about the CMS measurement (23-09-2024)
  11. CERN article about the CMS measurement

Gallery

Dinner out in Pisa after a seminar (Oct. 2022)
At the MIT campus during the CMS W mass Hackathon (Jan. 2023)
Social dinner during the CMS W mass Hackathon (Jan. 2023)
In front of Aula Magna of Area Pontecorvo in Pisa (Spring 2023)
A Zoom meeting during Summer 2024
At the CERN W mass seminar (Sept. 17th 2024)
A tea moment at INFN Pisa (Fall 2024)
During CMS Italy 2024 in Rome (Oct. 2024)
Dinner out in Pisa (Dec. 2024)

Contact

Prof. Lorenzo Bianchini
Dipartimento di Fisica "E. Fermi",
Largo Bruno Pontecorvo 3, 56127 Pisa (Italy)
email: lorenzo.bianchini@unipi.it
egroup: cms-erc-asymow@cern.ch