May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

Precise measurement on hypertriton and anti-hypertriton masses and lifetimes with the Heavy Flavor Tracker and the production of triton in Au+Au collisions at STAR

May 15, 2018, 3:40 PM
Sala Volpi, 1st Floor (Palazzo del Casinò)

Sala Volpi, 1st Floor

Palazzo del Casinò

Parallel Talk Thermodynamics and hadron chemistry Thermodynamics and hadron chemistry


Peng Liu (SINAP&BNL)


The Hyperon-Nucleon (Y-N) interactions play an important role for understanding the strong interaction. It is suggested that alternative Y-N couplings can be a possible solution to the recent observations of neutron star exceeding two solar masses, the so-called "hyperon puzzle". A precise measurement of masses and lifetimes of hypertriton and anti-hypertriton can enrich our knowledge on Y-N interactions. In addition, the light nuclei distributions provide an excellent tool for understanding the freeze-out conditions of system created in high-energy nuclear collisions. For example, the yield ratio of triton, $N(t)$, deuteron, $N(d)$, and proton, $N(p)$, which is defined as $N(t)N(p)/N^2(d)$ may be utilized as an alternative variable in the search of the QCD critical point.

In this talk, we will present the first precise measurement of hypertriton and anti-hypertriton masses in heavy-ion collisions at STAR with the Heavy Flavor Tracker (HFT). Hypertritons and anti-hypertritons are reconstructed through both two-body decay channel ($^3He+\pi^-$) and three-body decay channel ($p+d+\pi^-$) using the high-statistics data collected in 2014 and 2016 Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The binding energies and lifetimes of the (anti-)hypertriton will be extracted from this precise measurement. We will also present the centrality dependence of the mid-rapidity $p_T$ spectra of triton ($t$) from Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, 200 GeV. The collision energy and centrality dependence of the yield ratio, $N(t)N(p)/N^2(d)$, and the coalescence parameters of $d$ ($A$ = 2) and $t$ ($A$ = 3) will be also presented. Physics implications of these measurements will be discussed.

Content type Experiment
Centralised submission by Collaboration Presenter name already specified
Collaboration STAR

Primary author

Zhenyu Ye (University of Illinois at Chicago)

Presentation materials