English
Related papers

Related papers: Lepton flavour universality tests at LHCb

200 papers

It has been five years since the data sample from the LHCb detector, the first experiment optimized for heavy-flavor physics studies at a hadronic collider, was completed. These data led to many major discoveries in exotic hadron…

High Energy Physics - Experiment · Physics 2024-03-08 Daniel Johnson , Ivan Polyakov , Tomasz Skwarnicki , Mengzhen Wang

Heavy flavour is mainly produced during the initial hard partonic interactions in a heavy ion collision, and is well-suited to probe the early phases of the evolution of the system. This contribution will focus on Pb--Pb analyses at a…

High Energy Physics - Experiment · Physics 2019-08-13 Chiara Zampolli

Measurements of lepton flavor universality (LFU) and searches for charged lepton flavor violation (cLFV) are one of the most straightforward ways of searching for Beyond Standard Model (BSM) physics. The numerous production of top quark…

High Energy Physics - Experiment · Physics 2026-01-08 Normunds Ralfs Strautnieks

Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS…

High Energy Physics - Phenomenology · Physics 2016-06-23 Andreas Crivellin

The flavor-changing neutral current semileptonic decays of $B$ mesons provide an excellent platform for indirectly probing New Physics (NP) beyond the Standard Model (SM). Recent measurements of lepton flavor universality (LFU) ratios such…

High Energy Physics - Phenomenology · Physics 2026-01-08 Md Isha Ali , Utpal Chattopadhyay , Dilip Kumar Ghosh , N Rajeev

Searches for lepton flavor violation (LFV) stand at the forefront of experimental particle physics research, offering a sensitive probe to many scenarios of physics beyond the Standard Model. The high proton-proton collision energy and…

High Energy Physics - Experiment · Physics 2024-03-20 Jian Wang

The Littlest Higgs Model with T-parity (LHT) belongs to the simplest new physics scenarios with new sources of flavour and CP violation. We present a new analysis of quark observables in the LHT model in view of the oncoming flavour…

High Energy Physics - Phenomenology · Physics 2016-04-07 Monika Blanke , Andrzej J. Buras , Stefan Recksiegel

Normalizing the recent LHCb measurement of $\Lambda_b \to \Lambda_c \tau \bar\nu$ to the standard model (SM) prediction for the $\Lambda_b \to \Lambda_c \mu \bar\nu$ rate, instead of a LEP measurement, provides a more consistent comparison…

High Energy Physics - Phenomenology · Physics 2023-01-25 Florian U. Bernlochner , Zoltan Ligeti , Michele Papucci , Dean J. Robinson

We construct a semi-inclusive Lepton Flavour Universality (LFU) ratio, $R_\Sigma$, to test $\mu/e$ universality in $b\to s\ell^+\ell^-$ transitions at $e^+e^-$ $B$-meson factories. Combining different decay channels, this observable…

High Energy Physics - Phenomenology · Physics 2022-12-07 Marco Ardu , Gino Isidori , Marko Pesut

A precision test of lepton flavour universality has been performed by measuring the ratio RK of kaon leptonic decay rates K+ --> e+nu and K+ --> mu+nu in a sample of 59813 reconstructed K+ --> e+nu candidates with (8.71 +- 0.24)% background…

High Energy Physics - Experiment · Physics 2011-03-28 C. Lazzeroni et al.

We present a measurement of angular observables and a test of lepton flavor universality in the $B\to K^\ast \ell^+\ell^-$ decay, where $\ell$ is either $e$ or $\mu$. The analysis is performed on a data sample corresponding to an integrated…

High Energy Physics - Experiment · Physics 2016-12-16 Belle Collaboration , S. Wehle , C. Niebuhr , S. Yashchenko , I. Adachi , H. Aihara , S. Al Said , D. M. Asner , V. Aulchenko , T. Aushev , R. Ayad , T. Aziz , V. Babu , A. M. Bakich , V. Bansal , E. Barberio , W. Bartel , P. Behera , B. Bhuyan , J. Biswal , A. Bobrov , A. Bondar , G. Bonvicini , A. Bozek , M. Bračko , T. E. Browder , D. Červenkov , P. Chang , V. Chekelian , A. Chen , B. G. Cheon , K. Chilikin , R. Chistov , K. Cho , Y. Choi , D. Cinabro , N. Dash , J. Dingfelder , Z. Drásal , D. Dutta , S. Eidelman , D. Epifanov , H. Farhat , J. E. Fast , T. Ferber , B. G. Fulsom , V. Gaur , N. Gabyshev , A. Garmash , R. Gillard , P. Goldenzweig , B. Golob , O. Grzymkowska , E. Guido , J. Haba , T. Hara , K. Hayasaka , H. Hayashii , M. T. Hedges , W. -S. Hou , C. -L. Hsu , T. Iijima , K. Inami , G. Inguglia , A. Ishikawa , R. Itoh , Y. Iwasaki , W. W. Jacobs , I. Jaegle , H. B. Jeon , Y. Jin , D. Joffe , K. K. Joo , T. Julius , A. B. Kaliyar , K. H. Kang , G. Karyan , P. Katrenko , T. Kawasaki , H. Kichimi , C. Kiesling , D. Y. Kim , H. J. Kim , J. B. Kim , K. T. Kim , M. J. Kim , S. H. Kim , K. Kinoshita , L. Koch , P. Kodyš , S. Korpar , D. Kotchetkov , P. Križan , P. Krokovny , T. Kuhr , R. Kulasiri , T. Kumita , A. Kuzmin , Y. -J. Kwon , J. S. Lange , C. H. Li , L. Li , Y. Li , L. Li Gioi , J. Libby , M. Lubej , T. Luo , M. Masuda , T. Matsuda , K. Miyabayashi , H. Miyake , R. Mizuk , G. B. Mohanty , T. Mori , R. Mussa , E. Nakano , M. Nakao , T. Nanut , K. J. Nath , Z. Natkaniec , M. Nayak , N. K. Nisar , S. Nishida , S. Ogawa , H. Ono , Y. Onuki , G. Pakhlova , B. Pal , C. -S. Park , C. W. Park , H. Park , S. Paul , L. Pesántez , L. E. Piilonen , C. Pulvermacher , J. Rauch , M. Ritter , A. Rostomyan , Y. Sakai , S. Sandilya , L. Santelj , T. Sanuki , Y. Sato , V. Savinov , T. Schlüter , O. Schneider , G. Schnell , C. Schwanda , A. J. Schwartz , Y. Seino , K. Senyo , O. Seon , I. S. Seong , M. E. Sevior , C. P. Shen , T. -A. Shibata , J. -G. Shiu , B. Shwartz , F. Simon , R. Sinha , E. Solovieva , M. Starič , J. F. Strube , K. Sumisawa , T. Sumiyoshi , M. Takizawa , U. Tamponi , F. Tenchini , T. Tsuboyama , M. Uchida , T. Uglov , Y. Unno , S. Uno , P. Urquijo , Y. Ushiroda , Y. Usov , S. E. Vahsen , C. Van Hulse , G. Varner , K. E. Varvell , V. Vorobyev , A. Vossen , E. Waheed , C. H. Wang , M. -Z. Wang , P. Wang , M. Watanabe , Y. Watanabe , E. Widmann , K. M. Williams , E. Won , H. Yamamoto , Y. Yamashita , H. Ye , Y. Yook , C. Z. Yuan , Y. Yusa , Z. P. Zhang , V. Zhilich , V. Zhukova , V. Zhulanov , M. Ziegler , A. Zupanc

We confront the indications of lepton flavor universality (LFU) violation observed in semi-tauonic $B$ meson decays with new physics (NP) searches using high $p_T$ tau leptons at the LHC. Using effective field theory arguments we correlate…

High Energy Physics - Phenomenology · Physics 2016-11-15 Darius A. Faroughy , Admir Greljo , Jernej F. Kamenik

Hadrons carrying open heavy flavor, i.e. single charm or bottom quarks, are among the key diagnostic tools available today for the hot and dense state of strongly interacting matter which is produced in collisions of heavy atomic nuclei at…

Nuclear Experiment · Physics 2015-05-18 R. Averbeck

Quarkonia and open heavy flavour production are crucial to study the properties of the nuclear matter at high energy densities and of the Quark Gluon Plasma (QGP). In proton-proton collisions at LHC, the measurement of their production…

High Energy Physics - Experiment · Physics 2019-08-13 Raphael Tieulent

The flavor changing decays of heavy bottom quarks to the corresponding lighter quarks ($u$, $c$ and $s$) in various $B$-meson decays via charged current and neutral current semileptonic transitions have emerged as promising candidates to…

High Energy Physics - Phenomenology · Physics 2019-08-28 N Rajeev , Rupak Dutta , Suman Kumbhakar

Hints of lepton flavor violation have been observed by LHCb in the rate of the decay $B\to K\mu^+\mu^-$ relative to that of $B\to K e^+e^-$. This can be explained by new scalars and fermions which couple to standard model particles and…

High Energy Physics - Phenomenology · Physics 2018-06-27 James M. Cline , Jonathan M. Cornell

A new algorithm based on a deep neural network, DeepSets, for tagging the production flavour of neutral $B^0$ and $B^0_s$ mesons in proton-proton collisions is presented. Exploiting a comprehensive set of tracks associated with the…

High Energy Physics - Experiment · Physics 2026-02-18 J. E. Blank

We perform a model-independent global fit to $b\to s\ell^+\ell^-$ observables to confirm existing New Physics (NP) patterns (or scenarios) and to identify new ones emerging from the inclusion of the updated LHCb and Belle measurements of…

In these proceedings we discuss a flavor-safe explanation of the anomaly found in $R_K= {\cal B}(B \to K \mu^+ \mu^-)/{\cal B}(B \to K e^+ e^-)$ by LHCb, within the framework of composite Higgs models. We present a model featuring a…

High Energy Physics - Phenomenology · Physics 2016-10-20 Adrian Carmona , Florian Goertz

Lepton flavor universality can be tested through the ratio of semileptonic $B$ meson decays and leptonic $\Upsilon$ meson decays, with $\Upsilon \equiv \Upsilon(nS)$ ($n=1,2,3$). For the charged-current transitions $b \to…

High Energy Physics - Phenomenology · Physics 2021-04-22 Cristian H. García-Duque , J. H. Muñoz , Néstor Quintero , Eduardo Rojas