Publications associées à B-factory

Search for the lepton flavour violating decays B0→e±μ∓ and B0s→e±μ∓ with LHCb Run 2 data

A large variety of new physics models suggest that the rates for lepton flavour violating

b

-hadron decays may be much higher than predicted in the Standard Model, which leads to a high interest in the search for such decays. This thesis presents the se ...

EPFL2024

Development of microlens-enhanced SiPMs for a radiation-hard scintillating fibre tracker at LHCb

Carina Trippl

he LHCb experiment at CERN's Large Hadron Collider (LHC) is currently taking data with a newly developed Scintillating Fibre (SciFi) Tracker read out with multichannel silicon photomultipliers (SiPMs). The innermost fibre modules, exposed to the highest ra ...

EPFL2023

Measurement of the B+ -> rho0 mu+ nu differential branching fraction

Veronica Sølund Kirsebom

The tension between different determinations of the CKM matrix element Vub using measurements of either exclusive or inclusive semileptonic decays represents a long-standing puzzle in flavour physics. To resolve this, measurements of new exclusive channels ...

EPFL2023

Search for Heavy Neutral Leptons with LHCb

Serhii Cholak

This thesis presents a search for a beyond the Standard Model (SM) heavy neutral lepton (HNL), which does not interact via any of the SM interactions. This hypothetical particle has been proposed by multiple theories as an extension to the SM, and it could ...

EPFL2023

Testing lepton flavour universality in $B^+\to K^+\pi^+\pi^-\ell^+\ell^-$ decays with LHCb

Sara Celani

This PhD thesis aims at testing one of the fundamental properties of the Standard Model (SM) of particle physics: the lepton flavour universality (LFU), which states that

W

and

Z

bosons are equally coupled to the three lepton generations. In this work, ...

EPFL2023

Measurement of lepton universality parameters in B+→K+ℓ+ℓ− and B0→K*0ℓ+ℓ− decays

A simultaneous analysis of the

B^+\to K^+\ell^+\ell^-

and

B^0\to K^{*0}\ell^+\ell^-

decays is performed to test muon-electron universality in two ranges of the square of the dilepton invariant mass,

q^2

. The measurement uses a sample of beauty meson ...

2023

Test of Lepton Universality in b→sℓ+ℓ− Decays

The first simultaneous test of muon-electron universality using

B^{+}\rightarrow K^{+}\ell^{+}\ell^{-}

and

B^{0}\rightarrow K^{*0}\ell^{+}\ell^{-}

decays is performed, in two ranges of the dilepton invariant-mass squared,

q^{2}

. The analysis uses bea ...

2023

Precision measurement of neutral charm meson mixing parameters

Guillaume Max Pietrzyk

This thesis presents a measurement of the neutral charm meson mixing parameters

y_{C\!P}^{KK} - y_{C\!P}^{K\pi}

and

y_{C\!P}^{\pi\pi} - y_{C\!P}^{K\pi}

using

D^0 \rightarrow K^-K^+

,

D^0 \rightarrow \pi^-\pi^+

and

D^0 \rightarrow K^-\pi^+

decays. ...

EPFL2022

Model-independent measurement of charm mixing parameters in D0 -> K0S pi+ pi- decays

Surapat Ek-In

This thesis presents a measurement of charm mixing and CP-violation parameters using D0 -> K0S pi+ pi- decays. These mixing parameters include the mass and decay-width differences of the mass eigenstates of the D0-D0bar system. A search for Charge-Parity v ...

EPFL2022

A parametrized Kalman filter for fast track fitting at LHCb

Michel De Cian

We present an alternative implementation of the Kalman filter employed for track fitting within the LHCb experiment. It uses simple parametrizations for the extrapolation of particle trajectories in the field of the LHCb dipole magnet and for the effects o ...

2021

Evidence of a J/psi Lambda structure and observation of excited Xi(-) states in the Xi(-)(b) -> J/psi Lambda K- decay

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Chao Wang, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Ho Ling Li, Guido Haefeli, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Maurizio Martinelli, Vladislav Balagura, Liang Sun, Lesya Shchutska, François Fleuret, Liupan An, Renato Quagliani, Maxime Schubiger, Hang Yin, Preema Rennee Pais, Aravindhan Venkateswaran, Elena Graverini, Michel De Cian, Vladimir Macko, Federico Leo Redi, Sebastian Schulte, Tommaso Colombo, Donal Patrick Hill, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Pietro Marino, Maria Vieites Diaz, Marie Theres Christin Bachmayer, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Serhii Cholak, Veronica Sølund Kirsebom, Ettore Zaffaroni, Maria Elena Stramaglia, Surapat Ek-In, Ana Bárbara Rodrigues Cavalcante, Sara Celani, Katharina Müller, Carina Trippl, Arnout Lodewijk M Beckers, Sonia Amina Bouchiba, Thi Dung Nguyen, Maxim Karpov, Alison Maria Tully, Mâu Chung Nguyên, Maarten Willibrord Uriël Van Dijk, Simone Meloni, Xiaoqing Zhou, Elisabeth Maria Niel, Alexandre Brea Rodriguez, Marco Guarise

First evidence of a structure in the J/psi Lambda invariant mass distribution is obtained from an amplitude analysis of Xi(-)(b) -> J/psi Lambda K- decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with ...

2021

Branching Fraction Measurements of the Rare B-s(0) -> phi mu(+)mu(-) and B-s(0)-> f(2)' (1525)mu(+)mu(-) Decays

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Chao Wang, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Ho Ling Li, Guido Haefeli, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Maurizio Martinelli, Vladislav Balagura, Liang Sun, Lesya Shchutska, François Fleuret, Liupan An, Renato Quagliani, Maxime Schubiger, Hang Yin, Preema Rennee Pais, Aravindhan Venkateswaran, Elena Graverini, Michel De Cian, Vladimir Macko, Federico Leo Redi, Sebastian Schulte, Tommaso Colombo, Donal Patrick Hill, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Maria Vieites Diaz, Marie Theres Christin Bachmayer, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Serhii Cholak, Veronica Sølund Kirsebom, Ettore Zaffaroni, Maria Elena Stramaglia, Surapat Ek-In, Ana Bárbara Rodrigues Cavalcante, Sara Celani, Carina Trippl, Arnout Lodewijk M Beckers, Sonia Amina Bouchiba, Thi Dung Nguyen, Maxim Karpov, Alison Maria Tully, Mâu Chung Nguyên, Maarten Willibrord Uriël Van Dijk, Simone Meloni, Xiaoqing Zhou, Elisabeth Maria Niel, Alexandre Brea Rodriguez, Marco Guarise

The branching fraction of the rare B-s(0) -> phi mu(+)mu(-) decay is measured using data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 6 fb(-1), respectively. The bran ...

2021

Observation of New Resonances Decaying to J=Psi K plus and J=Psi phi

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Chao Wang, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Ho Ling Li, Guido Haefeli, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Maurizio Martinelli, Vladislav Balagura, Liang Sun, Lesya Shchutska, François Fleuret, Liupan An, Renato Quagliani, Maxime Schubiger, Hang Yin, Preema Rennee Pais, Aravindhan Venkateswaran, Elena Graverini, Michel De Cian, Vladimir Macko, Federico Leo Redi, Sebastian Schulte, Tommaso Colombo, Donal Patrick Hill, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Pietro Marino, Marie Theres Christin Bachmayer, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Serhii Cholak, Veronica Sølund Kirsebom, Ettore Zaffaroni, Maria Elena Stramaglia, Surapat Ek-In, Ana Bárbara Rodrigues Cavalcante, Sara Celani, Carina Trippl, Sonia Amina Bouchiba, Thi Dung Nguyen, Maxim Karpov, Alison Maria Tully, Mâu Chung Nguyên, Maarten Willibrord Uriël Van Dijk, Simone Meloni, Xiaoqing Zhou, Elisabeth Maria Niel, Alexandre Brea Rodriguez, Marco Guarise

The first observation of exotic states with a new quark content ccus decaying to the J/Psi K+ final state is reported with high significance from an amplitude analysis of the B+-> J/ Psi phi K+ decay. The analysis is carried out using proton-proton collisi ...

2021

Angular analysis of B0->D-Ds+ with Ds+-> Ds+gamma decays

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Chao Wang, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Ho Ling Li, Guido Haefeli, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Maurizio Martinelli, Vladislav Balagura, Liang Sun, Lesya Shchutska, François Fleuret, Liupan An, Renato Quagliani, Maxime Schubiger, Hang Yin, Preema Rennee Pais, Aravindhan Venkateswaran, Elena Graverini, Michel De Cian, Vladimir Macko, Federico Leo Redi, Sebastian Schulte, Tommaso Colombo, Donal Patrick Hill, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Maria Vieites Diaz, Marie Theres Christin Bachmayer, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Serhii Cholak, Veronica Sølund Kirsebom, Ettore Zaffaroni, Maria Elena Stramaglia, Surapat Ek-In, Ana Bárbara Rodrigues Cavalcante, Sara Celani, Carina Trippl, Arnout Lodewijk M Beckers, Sonia Amina Bouchiba, Thi Dung Nguyen, Maxim Karpov, Alison Maria Tully, Mâu Chung Nguyên, Maarten Willibrord Uriël Van Dijk, Simone Meloni, Xiaoqing Zhou, Valérie Jeanne Thérèse Renaudin-Schouler, Elisabeth Maria Niel, Alexandre Brea Rodriguez, Marco Guarise

The first full angular analysis of the B0 -> D-Ds+ decay is performed using 6 fb(-1) of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The Ds+-> Ds+gamma and D*- -> D0- vector meson decays ar ...

Springer Nature2021

Measurement of the prompt-production cross-section ratio sigma(chi(c2))/sigma(chi(c1)) in pPb collisions at root s(NN)=8.16 TeV

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Chao Wang, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Ho Ling Li, Guido Haefeli, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Maurizio Martinelli, Vladislav Balagura, Liang Sun, Lesya Shchutska, François Fleuret, Liupan An, Renato Quagliani, Maxime Schubiger, Hang Yin, Preema Rennee Pais, Aravindhan Venkateswaran, Elena Graverini, Michel De Cian, Vladimir Macko, Federico Leo Redi, Sebastian Schulte, Tommaso Colombo, Donal Patrick Hill, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Pietro Marino, Maria Vieites Diaz, Marie Theres Christin Bachmayer, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Serhii Cholak, Veronica Sølund Kirsebom, Ettore Zaffaroni, Maria Elena Stramaglia, Surapat Ek-In, Ana Bárbara Rodrigues Cavalcante, Sara Celani, Carina Trippl, Arnout Lodewijk M Beckers, Sonia Amina Bouchiba, Thi Dung Nguyen, Maxim Karpov, Alison Maria Tully, Mâu Chung Nguyên, Maarten Willibrord Uriël Van Dijk, Simone Meloni, Xiaoqing Zhou, Elisabeth Maria Niel, Alexandre Brea Rodriguez, Marco Guarise

This article reports the first measurement of prompt chi(c1) and chi(c2) charmonium production in nuclear collisions at Large Hadron Collider energies. The cross-section ratio sigma(chi(c2))/sigma(chi(c1)) is measured in pPb collisions at root s(NN) = 8.16 ...

2021

First indication of the Lambda-b baryon decay to a charmless baryonic final state

Vladimir Macko

The Standard Model of particle physics provides predictions of many fundamental processes. One of them is the existence of charmless processes involving only baryons, namely charmless purely baryonic decays of baryons. Yet none of these decay modes has bee ...

EPFL2021

Measurement of Xi(++)(cc) production in pp collisions at root s=13 TeV

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Ho Ling Li, Guido Haefeli, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Maurizio Martinelli, Vladislav Balagura, Donal Patrick Hill, Liang Sun, Lesya Shchutska, François Fleuret, Mirco Dorigo, Liupan An, Renato Quagliani, Hang Yin, Guido Andreassi, Aravindhan Venkateswaran, Elena Graverini, Michel De Cian, Vladimir Macko, Federico Leo Redi, Luis Miguel Garcia Martin, Sebastian Schulte, Tommaso Colombo, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Pietro Marino, Maria Vieites Diaz, Matthieu Philippe Luther Marinangeli, Serhii Cholak, Veronica Sølund Kirsebom, Maria Elena Stramaglia, Surapat Ek-In, Ana Bárbara Rodrigues Cavalcante, Luca Pescatore, Sara Celani, Preema Rennee Pais, Maxime Schubiger, Plamen Hristov Hopchev, Carina Trippl, Thi Dung Nguyen, Alison Maria Tully, Olivier Göran Girard, Mâu Chung Nguyên, Simone Meloni, Xiaoqing Zhou, Elisabeth Maria Niel, Alexandre Brea Rodriguez

The production of Xi(++)(cc) baryons in proton-proton collisions at a centre-of-mass energy of root s = 13 Tev is measured in the transverse-momentum range 4 < p(T) < 15 GeV/c and the rapidity range 2.0 < y < 4.5. The data used in this measurement correspo ...

IOP PUBLISHING LTD2020

Search for CP violation in Xi(+)(c) -> pK(-) pi(+) decays using model-independent techniques

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Guido Haefeli, Jessica Prisciandaro, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Greig Alan Cowan, Maurizio Martinelli, Vladislav Balagura, Donal Patrick Hill, Liang Sun, François Fleuret, Mirco Dorigo, Liupan An, Elena Graverini, Renato Quagliani, Hang Yin, Maria Vieites Diaz, Aravindhan Venkateswaran, Michel De Cian, Vladimir Macko, Federico Leo Redi, Luis Miguel Garcia Martin, Sebastian Schulte, Tommaso Colombo, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Pietro Marino, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Veronica Sølund Kirsebom, Maria Elena Stramaglia, Ana Bárbara Rodrigues Cavalcante, Guido Andreassi, Luca Pescatore, Preema Rennee Pais, Maxime Schubiger, Plamen Hristov Hopchev, Chitsanu Khurewathanakul, Thi Dung Nguyen, Olivier Göran Girard, Mâu Chung Nguyên, Axel Kuonen, Vincenzo Battista, Conor Thomas Fitzpatrick, Brice Emile Maurin

A first search for CP violation in the Cabibbo-suppressed Xi(+)(c) -> pK(-) pi(+) decay is performed using both a binned and an unbinned model-independent technique in the Dalitz plot. The studies are based on a sample of protonproton collision data, corre ...

SPRINGER2020

Measurement of the branching fraction of the decay B-s(0) -> (KSKS0)-K-0

Jian Wang, Mingkui Wang, Olivier Schneider, Zhirui Xu, Yiming Li, Yi Zhang, Lei Zhang, Yi Wang, Aurelio Bay, Guido Haefeli, Jessica Prisciandaro, Tatsuya Nakada, Christoph Frei, Mark Tobin, Frédéric Blanc, Greig Alan Cowan, Maurizio Martinelli, Vladislav Balagura, Donal Patrick Hill, Liang Sun, François Fleuret, Mirco Dorigo, Liupan An, Elena Graverini, Chitsanu Khurewathanakul, Renato Quagliani, Hang Yin, Maria Vieites Diaz, Aravindhan Venkateswaran, Michel De Cian, Vladimir Macko, Federico Leo Redi, Luis Miguel Garcia Martin, Sebastian Schulte, Tommaso Colombo, Vitalii Lisovskyi, Tara Nanut, Minh Tâm Tran, Violaine Bellée, Guillaume Max Pietrzyk, Pavol Stefko, Pietro Marino, Lino Ferreira Lopes, Matthieu Philippe Luther Marinangeli, Veronica Sølund Kirsebom, Maria Elena Stramaglia, Ana Bárbara Rodrigues Cavalcante, Guido Andreassi, Luca Pescatore, Preema Rennee Pais, Maxime Schubiger, Plamen Hristov Hopchev, Thi Dung Nguyen, Olivier Göran Girard, Mâu Chung Nguyên, Axel Kuonen, Vincenzo Battista, Conor Thomas Fitzpatrick, Brice Emile Maurin

A measurement of the branching fraction of the decay B-s(0) -> (KSKS0)-K-0 is performed using proton- proton - collision data corresponding to an integrated luminosity of 5 fb(-1) collected by the LHCb experiment between 2011 and 2016. The branching fracti ...

American Physical Society2020

Amplitude analysis for the measurement of the photon polarisation in B rightarrow K pi pi gamma decays

Violaine Bellée

This work proposes a method to measure the photon polarisation in

B^+ \rightarrow K^+ \pi^- \pi^+ \gamma

decays and prepares the necessary elements for this measurement using the data sets collected by the LHCb experiment at CERN in

2011

,

2012

, $2016 ...

EPFL2020