STAR researchers at Brookhaven National Laboratory found that correlations between charged particles’ sideways momentum changed nonmonotonically as they varied the energy of fixed-target gold-on-gold collisions. The pattern, measured in central collisions, may be sensitive to the QCD critical point—but it is not evidence that scientists have found or confirmed that point.
What did the researchers find?
The STAR Collaboration measured correlations in the transverse momentum of charged particles produced when gold nuclei collided. Transverse momentum is motion sideways to the beam direction. The team examined whether particles from the same collision tended to have related sideways momentum, then compared that relationship across collision energies.
As an Amazon Associate I earn from qualifying purchases.
In central collisions—events in which the nuclei collide with substantial overlap—the correlations followed a nonmonotonic energy dependence: rather than changing smoothly as collision energy changed, the pattern varied in an unexpected way. The study covered fixed-target Au+Au collisions at 3.0–7.7 GeV per colliding nucleon pair in RHIC’s Beam Energy Scan Phase II program. The STAR paper was published in Physical Review Letters on September 22, 2026.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →How strong was the signal?
The collaboration reports approximately 5σ statistical significance for the nonmonotonic pattern in central-collision data. That figure describes the strength of the observed pattern under the statistical analysis; it is not a 5σ probability or confirmation that the QCD critical point exists.
#1 Best Overall
![[239 PCS] Organic Chemistry Model Kit | Molecular Model Kit for Students](https://m.media-amazon.com/images/I/511A7UN+wEL._SL160_.jpg)
- 𝐇𝐀𝐍𝐃𝐒-𝐎𝐍 𝐂𝐇𝐄𝐌𝐈𝐒𝐓𝐑𝐘 𝐋𝐄𝐀𝐑𝐍𝐈𝐍𝐆: Take chemistry beyond memorizing formulas with an interactive learning experience students can physically handle. Manipulating the pieces of this molecule kit gives learners a more engaging way to practice identifying atoms, connecting bonds, and studying molecular structures.
- 𝐓𝐔𝐑𝐍 𝟐𝐃 𝐃𝐈𝐀𝐆𝐑𝐀𝐌𝐒 𝐈𝐍𝐓𝐎 𝟑𝐃 𝐌𝐎𝐃𝐄𝐋𝐒: Make textbook structures easier to interpret by transforming flat molecular diagrams into physical 3D models. With the help of this chemistry modeling kit students can see the position of atoms and bonds from different angles, helping them better understand molecular shape and arrangement.
- 𝐁𝐔𝐈𝐋𝐃, 𝐄𝐗𝐏𝐋𝐎𝐑𝐄 & 𝐑𝐄𝐁𝐔𝐈𝐋𝐃: Encourage active discovery by letting students construct a structure, adjust its arrangement, and build it again for continued practice. The reusable pieces make it easy to explore different molecular configurations without needing a new model for every lesson.
- 𝐄𝐅𝐅𝐎𝐑𝐓𝐋𝐄𝐒𝐒 𝐀𝐒𝐒𝐄𝐌𝐁𝐋𝐘: Designed for smooth, straightforward model building, the pieces connect easily so students can spend less time figuring out how to assemble the kit and more time exploring chemistry. Simple construction also makes it convenient for repeated classroom or study use.
- 𝐆𝐈𝐕𝐄 𝐓𝐇𝐄 𝐆𝐈𝐅𝐓 𝐎𝐅 𝐃𝐈𝐒𝐂𝐎𝐕𝐄𝐑𝐘: Bring a creative twist to science gifting with this organic chemistry molecular model kit made for curious students, chemistry fans, and STEM enthusiasts. Whether for a birthday, classroom reward, holiday, or special occasion, it gives recipients something interesting to build, examine, and enjoy.
| Comparison | Reported significance | What it indicates |
|---|---|---|
| Central-collision data | Approximately 5σ | The reported nonmonotonicity in the measured correlations. |
| Transport-model calculations | Approximately 2σ | The comparison calculations do not show the same level of nonmonotonicity. |
| Mid-central collision data | Approximately 1.4σ | The authors say this comparison does not support a nonmonotonicity claim. |
The central, mid-central, and model results are distinct comparisons. The paper’s key observation is the pattern in central collisions; the weaker mid-central and model results do not establish the same effect in those cases.
Why might a momentum pattern matter for the QCD critical point?
Quantum chromodynamics (QCD) is the theory describing the strong interaction between quarks and gluons. Physicists use high-energy nuclear collisions to study how matter behaves under extreme conditions and to map its possible phases. A QCD critical point is a hypothesized endpoint in the boundary between phases of nuclear matter at high baryon density. Measurements that change with collision energy can help constrain the properties of that matter and may be sensitive to such a point.
Rank #2
- HOBBY MODEL KIT – Unassembled model packed in an envelope with easy to follow instructions. Ideal for ages 14 and up
- NO GLUE OR SOLDER NEEDED – Parts can be easily clipped from the metal sheets. Tweezers are the recommended tool for bending and twisting the connection tabs
- GOLD KINKAKU-JI – 3 Sheet Model with a moderate difficulty level. Once assembled, dimensions are 3.5"L x 2.36"W x 2.56"H (8.9 x 6 x 6.5 cm)
- FROM STEEL SHEETS TO 3D – Pop out the pieces and connect using tabs and holes. Includes illustrated instructions
- HIGHLY DETAILED ETCHED MODEL – Display your 3D model once completed - collect and build them all
STAR’s authors describe the result as providing new constraints on the equation of state at high baryon density and say it may be sensitive to a QCD critical point. That is a cautious interpretation, not a claim that the point was located: the measured observable is a nonmonotonicity in particle momentum correlations, while its possible connection to the critical point remains an interpretation.
What happens in a gold-nucleus collision?
Gold nuclei are gold atoms stripped of their electrons. When they collide at RHIC, the energy can create an extremely hot, dense state in which quarks and gluons—the constituents of protons and neutrons—move freely for a brief time. Brookhaven describes the resulting quark-gluon plasma as behaving more like a liquid than the ideal gas scientists initially expected. That broader RHIC finding supplies context for why researchers study these collisions; it is separate from STAR’s new momentum-correlation result.
Quick Recap
Best Value
- FOR BASIC TEACHING TO ADVANCED SCIENCE: 444 pieces molecular model kit, including 136 atoms, 158 bonds and 150 parts for Carbon-60(Fullerene), provides to students from Grade 7 to Graduate level.
- TWO CHEMICAL STRUCTURE MODELS: The ball-and-stick models use spheres to represent atoms and sticks to represent chemical bonds. In the space-filling model, the spheres are drawn to scale and are next to one another as atoms are in real molecules.
- CHEMISTRY EDUCATIONAL MOLECULE MODEL IN 3D: It can display chemical structure, molecular bond, and bond angle in all directions. Demonstrate fundamental molecular geometry, chemical molecular structure, stereochemistry with 3D modeling studies.
- EASY TO LEARN: The universal standard adopted for each atom's color makes it easier for you to use and learn. Atoms and chemical bonds combine tightly and firmly and can be easily disassembled by disconnecting tools.
- If you’re not in love with it for whatever reason, we’ll give you a full replacement or refund—no questions asked. If you have any doubt, please tell us. With nothing to worry about, or even to share with your friends, try it now.
Rank #4
- 【444PCS】This Chemistry Molecular Model Kit contains 136 atom pieces made up of different elements;154 bonds:long flexible bonds (good for double and triple bonds),medium-length hard bonds,short-bonds (used for scale model single bond),overlength bonds,V-bonds (for space-filling models);3 electronic cloud slice;1 complete fullerene model (60 carbon atom+90 bond);1 removing tool for easy to separate atoms from the links.With this set,it is easy to build models for organic and inorganic chemistry
- 【Non-Toxic Material】All materials of our 444PCS Organic Chemistry Model Kit are eco-friendly.Polypropylene atoms (pp plastic) feel smooth,no scraps or cutting edges from the holes;Low-Density Polyethylene links (LDPE plastic) are easy to remove and put on.The atom parts and links are color coded to national standards for ease of identification and come with an Instructional Guide to easily identify all atoms and connectors.Delivered in a sturdy plastic box for easy storage and portability!
- 【Fullerene Models】What makes Our 444PCS Chemistry Model Kit unique is that this Model Kit has a complete fullerene model made up of 60 carbon atoms and 90 bonds.Fullerene is the third isomorphic body found in elemental carbon.The structure of fullerene is similar to the representative work of architect Fuller,so it is called fullerene.This is a great set to be put high school,university chemistry in most of the organic or inorganic molecular structure model for the study of experimental operatio
- 【Making Chemistry Fun】This educational molecule modeling kit is designed for easy chemistry learning for organic,inorganic,o chem and functional groups.The color coded bonds and atoms help visually demonstrate the geometry and structure of compounds & other bond types,let intangible chemical molecules atomic shape transform into tangible,help teachers and parents to cultivate children's interest in chemistry,makes learning chemical 3D molecule or atomic structures fun and interactive
- 【Best Parent-Child Interaction】There is no doubt that maternal-child interaction plays a very important role in child development.It is a good interaction for parents and children.Parents show their kids how to build 3D molecule to explore chemistry and physics concepts,kids teach their family the magic of chemistry and share the education experience.The Molecular model kit is designed for all ages:students from grade 7 to the University Graduate Level,STEM teachers,parents
Rank #3
- ★ ADVANCED LEARNING SCIENCE EDUCATION KIT --- Perfect chemistry model kit for modeling simple and small to more advanced and complex chemical structures for schools and college level, students of all ages, researchers and enthusiasts. Fun and interactive early learning molecular set for kids of all years and for use in the classroom.
- ★ HIGH QUALITY --- Made from high quality durable materials designed for easy construction and perfect fit. These Molecular Model Kit pieces are color coded to national standards for easy ID. Organic Chemistry Model Kit includes box for easy storage and transport with your other textbooks, notes, and books. Excellent for the classroom.
- ★ POWERFUL FUNCTIONS --- This Molecular Model Kit has a total of 122 pieces including short link remover tool. Super easy to build models for organic and inorganic chemistry, This model contains C, H, O, N, S and a variety of single and double bonds, Can be put high school, university chemi stry in most of the organic or inorganic molecular structure model for the study of experimental operation.
- ★ QUICK AND EASY ASSEMBLY OF COMPLEX STRUCTURES --- Atoms and bonds that are perfectly suited to being connected and disconnected easily without making your fingers hurt. We've also included a link remover to make the task of easy.
- ★ CONVENIENT STORAGE --- The pieces come in a slim plastic box for convenient storage. See the pictures on this listing for a full understanding of what's inside!
What the result does—and does not—show
- It shows: STAR observed a statistically significant, nonmonotonic energy dependence in transverse-momentum correlations for central fixed-target gold-on-gold collisions across 3.0–7.7 GeV per colliding nucleon pair.
- It may suggest: The pattern could be sensitive to the QCD critical point and offers constraints on matter at high baryon density.
- It does not establish: That the QCD critical point has been discovered, or that the same nonmonotonicity is supported by the mid-central data or the transport-model calculations.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
